text:
Changing a creature's base Power and Toughness until End of Turn
I have a question regarding spells that change other creatures' base power and/or toughness (for example, 3/3). I'm asking because in a few days I will probably receive my Oko Planeswalker Deck from Throne of Eldraine edition, and I know there are some such cards in it.

When I have an instant that says target creature has base power and toughness, for instance, 3/3 and I cast it and it resolves, only base statistics change, correct? Do counters, attached enchantments or equipment, abilities, other effects stay on my creature?

This might get complicated, but it's covered by the layer system:

613.1. The values of an object’s characteristics are determined by starting with the actual object. For a card, that means the values of the characteristics printed on that card. For a token or a copy of a spell or card, that means the values of the characteristics defined by the effect that created it. Then all applicable continuous effects are applied in a series of layers in the following order:
...
613.1f Layer 6: Ability-adding effects, ability-removing effects, and effects that say an object can’t have an ability are applied.
613.1g Layer 7: Power- and/or toughness-changing effects are applied.
...
613.2. Within layers 1–6, apply effects from characteristic-defining abilities first (see rule 604.3), then all other effects in timestamp order (see rule 613.6). Note that dependency may alter the order in which effects are applied within a layer. (See rule 613.7.)
613.3. Within layer 7, apply effects in a series of sublayers in the order described below. Within each sublayer, apply effects in timestamp order. (See rule 613.6.) Note that dependency may alter the order in which effects are applied within a sublayer. (See rule 613.7.)
613.3a Layer 7a: Effects from characteristic-defining abilities that define power and/or toughness are applied. See rule 604.3.
613.3b Layer 7b: Effects that set power and/or toughness to a specific number or value are applied. Effects that refer to the base power and/or toughness of a creature apply in this layer.
613.3c Layer 7c: Effects that modify power and/or toughness (but don’t set power and/or toughness to a specific number or value) are applied.
613.3d Layer 7d: Power and/or toughness changes from counters are applied. See rule 122, “Counters.”

The effect you describe does not remove auras/equipments/counters from the creature. But it does affect what effect they have on the creature:
For abilities, it matters how/when the creature got them. A creature which is printed with flying (a characteristic-defining ability) will lose it due to Oko, Thief of Crowns's effect; the same holds for a creature which was already equipped with Angelic Armaments. If you equip the Armaments after Oko's ability, it will have flying.
The 3/3 effect is applied in Layer 7b (overwriting the power/toughness printed on the creature card); most effects you describe are applied in Layer 7c (but counters in Layer 7d), so they are applied later and do give bonuses (or penalties) on top of the 3/3.

Yes, most effects from auras, equipment and so on will stay unaffected.
In order to tell what the current characteristics of a permanent on the battlefield is, all the different effects that affect it are applied in a specific order, referred to as layers (irrelevant sections skipped):

613.1. The values of an object’s characteristics are determined by starting with the actual object. For a card, that means the values of the characteristics printed on that card. For a token or a copy of a spell or card, that means the values of the characteristics defined by the effect that created it. Then all applicable continuous effects are applied in a series of layers in the following order:
[...]
613.1g Layer 7: Power- and/or toughness-changing effects are applied.
[...]
613.3. Within layer 7, apply effects in a series of sublayers in the order described below. Within each sublayer, apply effects in timestamp order. (See rule 613.6.) Note that dependency may alter the order in which effects are applied within a sublayer. (See rule 613.7.)
[...]
613.3b Layer 7b: Effects that set power and/or toughness to a specific number or value are applied. Effects that refer to the base power and/or toughness of a creature apply in this layer.
613.3c Layer 7c: Effects that modify power and/or toughness (but don’t set power and/or toughness to a specific number or value) are applied.

So first we look at the actual printed card. It says 3/3. Then you have an effect that sets the power and toughness to 3/3, applied in layer 7b. Then, after that, you have all effects in layer 7c, where auras, equipment and other effects that grant +x/+y are applied (although many auras, equipment and other sources also grant effects that apply in other layers, like abilities, colour, change of controller or card type changes). Effects that go into layer 7b are always applied before effects that go into layer 7c, regardless of the actual order they were put into effect.

The answer is yes. I'll try to explain it as simple as possible:
First off, setting power/toughness never changes whether something is attached to, or stays on, your creature.
The rules tell you to do the following to calculate power/toughness (P/T) of a creature:

Start with the P/T printed on it, if there is a characteristic defining ability (CDA) for P/T on it, for example the creature might have a * in its P/T, then you have to read that ability to determine the P/T.
If there is any active effect setting base P/T, forget about what you got before and use this one instead.
If there is any active effect changing P/T like +1/+1 or -X/-0 where X is some number defined by the effect, apply it now.
Now add the change by counters (+1/+1 or -1/-1 mostly)
If there is any active effect exchanging P/T, do it now.(This one is added for completeness, but not mentioned in the question)

It gets slightly tricky, if two or more effects belong to a single step above. Then you apply those in "timestamp" order, that is, the older effect comes first. So if you set base P/T to 3/3, then 10/10 in the same turn "until end of turn", then the creature is 10/10, because the second effect applies second, overriding the first.


text:
How does murder interact with a creature being sacrificed?
if I cast murder on my opponent's creature that has a tap to sacrifice creature after he uses it's ability, does the activated ability happen?
My friends and I had a game where one of them used a tap ability to sacrifice this creature to deal 2 damage and I played murder.
In response does my creature die or his ability not go off since the sacrifice was not a part of the cost?

Which creature was this effect on? The specific wording is important.

Please clarify.

The instruction to sacrifice the creature will probably be either in the cost to activate the ability (before the ":") or be an effect (after the ":"). If it is a cost, which is usually the case, you will not be able to target it with murder if your opponent already used the ability. Sacrificing it is a cost to using the ability, meaning it is already dead by the time effect goes on the stack. If the sacrifice is part of the effect, you will be able to murder it before the ability resolves. (The creature will die either way, but it may be important that it wasn't sacrificed.)

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


text:
Can I cast an instant or activate an ability between "whenever a creature dies" triggers, if the creatures die at the same time?
Let's say I'm playing Dark Prophecy, which has an ability which states

Whenever a creature you control dies, you draw a card and you lose 1 life.

and I have a Naturalize in my hand.
Suppose I'm attacked, and lose 2 creatures in combat. Because of the combat damage I'll be taking, I can't afford to lose 2 extra life, but I can lose 1, and want the card draw. Can I cast Naturalize after letting it trigger just once, and destroy my own Dark Prophecy before it kills me?

No, you cannot.
Creatures die as a state-based action, which means they all die at the same time. This means the triggers from Dark Prophecy go on the stack at the same time. Since these all occur as part of the state-based actions, you can't "interrupt" the placing of the triggers on the stack and either you will get 2 triggers of Dark Prophecy or 0, depending on when you cast Naturalize.

No
All combat damage is dealt at the same time, which means that the two creatures will die at the same time, and each one will add a trigger from Dark Prophecy to the stack. At the end of combat damage, the stack will look like this:
[Top of Stack]
Dark Prophecy Trigger
Dark Prophecy Trigger
[Bottom of Stack]
You can decide which order these triggers go on the stack (they're the same so in this case it doesn't really matter), but since they go on at the same time, you don't have a chance to cast Naturalize before they are both on the stack.
You are correct in your thinking that you can cast naturalize after one trigger resolves. However, this doesn't really do what you want: Even though Dark Prophesy is destroyed from Naturalize, any triggers that are still on the stack will still resolve as normal.
As a side note, if the card you draw from the first Dark Prophecy can be cast at instant speed, you can use it before the second Dark Prophecy trigger resolves. This could be useful if the card you draw is some kind of instant speed life gain, such as Crypt Incursion

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Can Canopy Spider block Treetop Rangers?
I know that creatures that have "can't be blocked except by creatures with flying", like Treetop Rangers, can't be blocked by creatures with reach like Giant Spider since it does not have flying. What about creatures that don't have reach but have a description like "may block as though it had flying", for example Canopy Spider?
Basically, can Treetop Rangers be blocked by Canopy Spider even though it can't be blocked by Giant Spider?

No, Canopy Spider cannot block Treetop Ranger
In the errata of the card Canopy Spider, which appears to the right of the card image, the creature's text has been replaced with the Reach keyword. The errata text always overrules what is physically written on the card, so Canopy Spider has reach and no other abilities.
The rulings on Treetop Rangers specifically states that creatures without flying can't block it, even if they have reach.
It's important to check any older cards that seem to have a 'keyword before it was a keyword' to see if their text has changed, as there are quite a few.

The text “can block as though it had flying” does not exist on any cards any more; any cards that used to have it, such as Canopy Spider, have received errata to have Reach instead. Note that even Giant Spider was printed at one time with the “can block as though it had flying” text.
When determining the correct card text of any card, all that matters is what is written in the Oracle card database at gatherer.wizards.com. It does not matter which printed version of the card you are playing with.*
However, to answer your question in terms of MTG history, back when those cards did have that text, yes, they could block Treetop Rangers. This is because for the purposes of declaring them as blockers, you acted as though they had flying. The errata to use Reach changed this interaction.
Source:

Creatures with reach (and without flying) won't be able to block creatures that say they "can't be blocked except by creatures with flying," simply because those creatures don't actually have flying (and will no longer act as though they do). Cards affected by this change are Elven Riders, Silhana Ledgewalker, Treetop Bracers, Treetop Rangers, and Treetop Scout.

*The un-card R&D's Secret Lair aside.


text:
Lazav Ability on the Stack
I have gained control of my opponent's Lazav, the Multifarious. I activate it's ability targeting the Clone in my graveyard. If the ability resolves, Lazav will die, becoming a 0/0 with no abilities, as it didn't enter, and so is unable to copy anything.
My opponent, in a desperate measure to keep Lazav on the field, casts Dominate with Lazav's ability on the stack targeting Clone. He then proceeds to cast Essence Flux on the Lazav that he now controls, flickering it.
In this scenario, does removing the source of the ability (temporarily) stop it from resolving properly, thus fizzling the ability? Or would his ability resolve, targeting Clone, as Lazav is now back on the field?
Does it work the same as flickering the target of a spell to make it fizzle if you flicker the source of an activated ability in this manner?
Additionally, would the ability fizzle because Clone is now no longer in the graveyard of Lazav's controller, or does it only check the location of the Clone relative to who controlled Lazav when the ability was activated?

The Lazav that entered after Essence Flux is a new Lazav
Any old abilities that may be on the stack only see that the Lazav that they were supposed to change is no longer on the field.
This is similar to flickering the target of a spell or an ability to 'dodge' the ability (such as using Essence Flux to flicker a creature that is targeted by Murder) in that both interactions are governed by rule 400.7

400.7. An object that moves from one zone to another becomes a new object with no memory of, or relation to, its previous existence.

There are 9 exceptions to this rule, and none of them apply here.
If Lazav changes controllers with its ability on the stack, that ability will still resolve.
In the secondary question (assuming Lazav wasn't flickered), the ability that targets Clone in your graveyard will resolve. Although Lazav changed controllers, the ability on the stack did not change controllers. "Your" in Lazav's ability on the stack still refers to you (the player who previously had control of Lazav), and Clone is still in your graveyard, so it is still a legal target. That ability will still find Lazav, even though it changed controllers, because it didn't change zones.

Are you sure Lazav changing controler is enough for the ability to fizzle? The ability's controler doesn't change.

Yeah I believe the edit to this makes it incorrect...

Ah, that is true. I suppose to work the way I thought, Lazav's ability would have to be phrased something like "Lazav becomes a copy of target creature card in Lazav's controller's graveyard..."

The ability will still resolve (not fizzle), but it will have no effect when it does.

400.7. An object that moves from one zone to another becomes a new object with no memory of, or relation to, its previous existence. There are nine exceptions to this rule:

None of the exceptions apply here. When Lazav's ability resolves, it will attempt to make the Lazav who had its ability activated into a copy of Clone. But that Lazav no longer exists at all. There is now a different Lazav around, that has no connection to that other Lazav.
Simply changing controllers would not help here; the flickering is what makes Lazov a new object. Even if Lazov's controller changes, the ability on the stack is still controlled by you; which makes the Clone in your graveyard still a valid target.


text:
Why do player start with fighting for the corners in go?
I saw that in most go games the opponents started by placing chips 3 vertices away from the corners. Both players started fighting for the centre only after half of the game had passed. Is there any particular reasoning for this?

Common starting practices are to open by placing stones on a Hoshi (4-4 point), or close to it, in order to "claim" that corner. As the players are trying to secure as much area as they can, it makes sense to start out in a place that is easily defended, and that is something that's true for corners more than for any other location on the board at the start of the game.
Taking control of the center is much easier if the player has a solid base or even a number of solitary stones already placed, which obviously isn't the case at the start of the game. Furthermore, by trying to gain control of the center, your opponent would likely take all or most of the corners for themselves, which will eventually result in having to defend the center against all flanks.
In a real game, of course none of this will be this clearly separated, but those are the essentials it comes down to. Generally, you're not looking to immediately engage with your opponent, but rather to define areas of advantage for yourself first.
Because this question, just like most questions about Go, pose a larger complexity than would be feasible to go into here, I'll leave it at that and provide a few links that are likely to be reachable in the future to read further:

First moves
Open in the corner
Why don't we open at tengen

It should be noted that this is true for 19x19 boards - on 9x9 boards, you will much more commonly see players starting out at the Tengen (center starpoint), or at the very least try to compete for it much earlier on, simply because there isn't as much area to gain in the corners by comparison, and approaching the same strategy as on a 19x19 board would have you run into your opponent much faster than you'd like.

I would restate as "Generally, you're not looking to immediately engage with your opponent, but rather to define areas of advantage for yourself first." I believe this more accurately reflects the correct conceptual approach for an opening strategy. Otherwise quite good.

Capturing territory around the edges of the board is simpler and quicker, because the edge forms a boundary which does not have to be constructed with stones, and which can not be attacked from "outside".
Once a player has a safe territory attached to the edge, it can be extended towards the center of the board.
It is also relevant that a border just three stones wide around the entire edge of the board contains more than half the total board area. Of course a real game situation will be more complex than that simple piece of mathematics, but the general principle it demonstrates is important.

Because you need less stones in the corner to live than in the center. And by extension, you can surround more area in the corner with the same number of stones.
Some figures to visualize this:
Live group in the corner, 6 stones:
+------
|.xx..
|x.x..
|xx...
|....

Live group in the middle, 10 stones:
......
.xx...
.x.x..
.xx.x.
..xxx.
......

(See Smallest Group with Two Eyes on Sensei's Library.)
Those same 10 stones placed in the corner could cover much more points than they can in the middle:
+-------
|....x.
|.x..x.
|....x.
|....x.
|xxxxx.
|......

It is plain and simple that it is much easier and more efficient to make life groups and territory in the corners than along the edges or in the centre. In the corner, you need two outer walls, along the edge three, and in the center four to enclose your territory.
And Go is about enclosing territory, after all.


text:
How do I tune my magic arena (MTGA) deck for 3 lands in my opening hand, under the new mulligan rule and selection algorithm?
Is it 22 lands? Did I understand the algorithm correctly and did I draw the correct conclusions, or am I getting it wrong?
From what I have read, the arena algorithm takes 2 virtual copies of your deck, shuffles and draws a hand from each. It then picks the hand (and deck) with the ratio that is closest to the ratio in your deck.  (maybe i already got that wrong?).
21-land-deck with ratio = 0.350 (21 / 60)
1-land-hand -> ratio = 0.143 -> distance to deck ratio = 0.21
2-land-hand -> ratio = 0.286 -> distance to deck ratio = 0.06 -> 2-land-hand gets picked :(
3-land-hand -> ratio = 0.429 -> distance to deck ratio = 0.08

22-land-deck with ratio = 0.367 (22 / 60)
2-land-hand -> ratio = 0.286 -> distance to deck ratio = 0.08
3-land-hand -> ratio = 0.429 -> distance to deck ratio = 0.06 -> 3-land-hand gets picked :)
4-land-hand -> ratio = 0.571 -> distance to deck ratio = 0.20

So as I understand it, in a 21-land-deck, if one of the 2 opening hands contains 2 lands, it will always get picked if the other hand has a different number of lands.
And in a 22-land-deck, it's always the 3-land-hand that wins.
So it's 22 lands?
Resources:

https://www.channelfireball.com/articles/arenas-new-opening-hand-rule-has-radical-implications-for-how-we-play-the-game/

Update 2019-09-04:
I must say I changed back to 24 lands recently, because I was getting 2-land opening hands in what felt like more than 50% of the time, when it should have been closer to 30%. But I didn't actually record any numbers, so it might just be my perception.

From the page you reference:

It also means that 21 and 22 lands become very different amounts, since 21 or fewer land decks will favor 2-land hands, and 22+ land decks will favor 3-land hands.

So the cutoff is indeed 22 lands.

For a single draw, the distribution is (note that the figures in your reference are incorrectly rounded):
total     0       1       2       3       4       5       6       7
lands   lands    land   lands   lands   lands   lands   lands   lands
  18     7.0%   24.4%   33.7%   23.6%    9.1%    1.9%    0.2%    0.0%
  19     5.8%   22.1%   33.2%   25.4%   10.7%    2.5%    0.3%    0.0%
  20     4.8%   19.9%   32.4%   27.0%   12.4%    3.1%    0.4%    0.0%
  21     4.0%   17.7%   31.3%   28.3%   14.2%    3.9%    0.5%    0.0%
  22     3.3%   15.7%   30.0%   29.4%   16.0%    4.8%    0.7%    0.0%
  23     2.7%   13.8%   28.6%   30.3%   17.8%    5.8%    1.0%    0.1%
  24     2.2%   12.1%   26.9%   30.9%   19.6%    6.9%    1.3%    0.1%
  25     1.7%   10.5%   25.2%   31.2%   21.4%    8.2%    1.6%    0.1%

For the new Arena style it is instead (note that I think the figure in the reference article for drawing 2-4 lands from 20 is completely wrong):
total     0       1       2       3       4       5       6       7
lands   lands    land   lands   lands   lands   lands   lands   lands
  18     0.8%   14.9%   56.0%   25.8%    2.5%    0.0%    0.0%    0.0%
  19     0.7%   13.4%   55.4%   27.5%    3.0%    0.1%    0.0%    0.0%
  20     0.6%   12.2%   54.3%   29.2%    3.6%    0.1%    0.0%    0.0%
  21     0.5%   11.2%   52.8%   30.9%    4.4%    0.2%    0.0%    0.0%
  22     0.2%    5.3%   33.4%   50.2%   10.4%    0.6%    0.0%    0.0%
  23     0.1%    4.5%   31.7%   51.4%   11.5%    0.8%    0.0%    0.0%
  24     0.1%    4.0%   30.0%   52.2%   12.7%    1.0%    0.0%    0.0%
  25     0.1%    3.6%   28.3%   52.6%   14.1%    1.2%    0.0%    0.0%

Here is Python 3 code to generate the tables. Run it online.
def binom(n, k):
    nCk = 1
    for i in range(k):
        nCk = nCk * (n - i) // (i + 1)
    return nCk

def hand_probability(deck_size, total_lands, hand_size, hand_lands):
    return binom(total_lands, hand_lands) * binom(deck_size - total_lands, hand_size - hand_lands) / binom(deck_size, hand_size)

if __name__ == "__main__":
    header_format = "{:^8}" * 9
    print("Normal")
    print(header_format.format("total", *list(range(8))))
    print(header_format.format("lands", "lands", "land", *["lands"] * 6))

    row_format = "{:^8}" + "{:^8.1%}" * 8
    for lands in range(18, 26):
        row = [hand_probability(60, lands, 7, k) for k in range(8)]
        print(row_format.format(lands, *row))

    print("")

    print("Arena")
    print(header_format.format("total", *list(range(8))))
    print(header_format.format("lands", "lands", "land", *["lands"] * 6))

    row_format = "{:^8}" + "{:^8.1%}" * 8
    for lands in range(18, 26):
        probs = [0] * 8
        for i in range(8):
            for j in range(8):
                winner = i if abs(i / 7 - lands / 60) <= abs(j / 7 - lands / 60) else j
                probs[winner] += hand_probability(60, lands, 7, i) * hand_probability(60, lands, 7, j)
        print(row_format.format(lands, *probs))

I was wondering whether the more math-y people from PPCG would eventually turn up on this question. Not disappointed.

Crazy jump, right? Care to show and explain the formula for the distribution?

Also, I am now going to keep book of the number of lands for each game and mulligan to verify this distribution experimentally. Currently I feel like I still get 2-land hands far too often.

@RetoHöhener, unfortunately this site doesn't seem to have MathJax configured. Would Python code be any use to you?

I don't really need it, I just felt like I couldn't mark your answer as accepted as long as it is unclear how you arrived at your numbers.


text:
Child's game where a picture behind a shutter is only visible for a split second
I'm looking for the name of a children's game where a picture behind a plastic shutter is visible only for a fraction of a second. The players sitting in front of the shutter then had to guess the picture.
I'm not looking for the game where single parts of a picture are revealed one after the other. The game I have in mind had a simple plastic mechanic, which opened and quickly closed again a shutter while making some clattering noises.

I finally found the game I had in mind. However, the picture is not revealed by a shutter as I originally asked, but by a rotating pole. The cluttering sound is simply induced by the plastic arm moving around.
The game from 1997 is called „Flip-Flap“ and published in Germany by „Ravensburger“.


text:
If tests are voluntary, why does one lose a life point automatically?
I'm a new owner of T.I.M.E Stories and about to play my first scenario within the next few weeks. However, studying the rules book (v 1.1) left me confused about the optionality of tests.
If I understood the rules correctly, activating a test is voluntary (see page 11)?:

"You  can  leave  the  card,  ignoring  the  test,  or  you  can  start  the  test,  then  drop it to go do something else."

For instance, a player reveals a card stating: "You can obtain item XY by attacking the guard." The test is on fighting with 3 shields and 2 red skulls. Moreover, there is no red lock on the card.
Can a player then simply do nothing, e.g. to wait for another/stronger player before activating the test?
What confuses me is the blue box on page 12:

"If you decide to do nothing during a test (because, for example, you
  do not have the required characteristic) and that test has at least
  one skull shield, your receptacle automatically loses 1 Life Point and
  the heart, time, and special shields take effect normally."

Does the player lose one life for ignoring the test or does this rule not apply since the test wasn't activated yet?
Let's follow this hypothetical card:
Two players are facing this card. Player A reads the card first and then activates the test by attacking the guard. Is the second player B on the card now obliged to do the test or can he simply do nothing without automatically losing one hit point?
Last but not least: How are tests handled if there is indeed a red lock on the card? Is the player then obliged to activate the test?
For instance, the card says: "A guard discovers your break-in and is immediately attacking you".
Do you then have to activate the test and put down the shields beneath the card or can one simply do nothing (without activating the test)? I'm aware of the fact, that one is not allowed to leave a card with a red lock, but I'm uncertain whether or not the player actually has to activate the test.
I already discovered this thread, but the discussion ended before this particular question was resolved.
TL;DR: When does the hint from page 12 actually apply?

This really looks like multiple questions to me.  You might be ahead to edit down to one question, and ask the others separately.

My post can be broken down to the question: "When does the hint from page 12 actually apply?". I simply gave some scenarios which are not fully clear to me.

Disclaimer: this answer is not well-sourced, but simply comes from my experience playing the game and my own understanding/reading of the rules.
For tests without a lock icon:
The "do nothing" text only applies if you have chosen to start the test. So you are allowed to simply stay in the space without being in the test. However, given that TU is your most precious resource in the game; it's hard to imagine a situation where you wouldn't be better off doing something with your TU rather than just standing still.
Each TU that is spent during a test can be spent in one of three ways:

Roll to attack/attempt the test.
Move to a new space.
Do nothing (this is when the blue box clarification applies).

In this situation, it is rare that this will matter; because you wouldn't have started the test if you were just going to do nothing during it. It could come up if 2 players were in the same space when a test is revealed, one of them doesn't have the required characteristic to roll, and they don't want to move somewhere else because they want to be in that space after the test ends.
For tests with a lock icon:
There is no option to start or not start the test. Simply by reading or revealing the card; you are now stuck in the test. The blue box text is more likely to apply in this situation, because you might find yourself stuck in a test where you don't have the required attribute needed to attempt a roll.


text:
What is the optimal way to roll for a two pair in Yahtzee?
Let’s say I’m playing Yahtzee and my aim is to get any two pair, the actual numbers don’t matter.
As usual, I can save any dice I want and re-roll the rest. Let’s say that my hand contains the following:  {1, 3, 3, 5, 6}
I have 3 options:

Re-roll everything and hope to get any two pair.
Save the two 3s and roll the rest. Rolling three dice and hoping to get any pair.
Save the two 3s as well as any other random number, let’s say the 5. Now rolling only two dice hoping to get a 5 or any other new pair.

Which of these strategies maximizes the probability of getting a two pair?

Optimal as in just getting 2 pairs or as well in maxing your points?

@Zibelas Just getting two pairs. Ignoring points.

Do you wish to maximize the chance of getting two pair, even if it reduces the chance of getting an "even better" result like a full house or Yahtzee? My gut feel is that the difference between (2) and (3) comes down to the chance of getting 3 or more 3s - e.g. if you keep the 5, you have zero chance of getting a Yahtzee.

@PhilipKendall That's a good question. For the sake of simplicity, let's just say that I want to maximize the chance of getting two pair even if it reduces the chance of getting a better result.

This is probably closer to being suited to the mathematics SE, but let's go through it.
Also, funnily enough as far as I can tell there is no scoring option for "Two Pairs" in Yahtzee as officially released by Hasbro. In Yatzy or Yacht, which are common variants released elsewhere, the values of the pairs must be distinct values, but the fifth die may be a copy of one of the pairs (i.e. you can score a Full House as Two Pairs, but not Four of a Kind). I will be working on that assumption here.
Rolling all
If you roll all 5 dice, then there are 6^5 = 7776 possible rolls.
To make Two Pair with an off-value 5th die, there are 6 ways to choose the off-value, and 10 possible choices for the values of the pairs. The off-value die can be any of 5 choices, and then there are 6 ways the two pairs could be placed among the other 4 dice. Hence there are 6x10x5x6 = 1800 ways to roll Two Pair with an off-value.
In addition, to make a Full House you have 6 choices of value for the triple, and 5 choices for the double (a Yatzy can't be scored as Two Pair). There are 10 ways to choose which dice form the double, so there are 300 ways to roll a Full House.
Hence, there are 1800+300=2100 ways to roll Two Pair, and a probability of 2100/7776 = 27.0% that you will do so.
Keeping the pair
If you just keep the pair of 3s, you're rolling 3 dice (of which there are 6^3 = 216 combinations) and hoping for either:

3 of the same value, not equal to 3.
A pair not equal to 3, and a value not equal to it (but possibly equal to 3).

For (1), there are 5 possible values for the triple, and for each of those there is exactly one way to roll it (since 111 can't be re-arranged to a different roll).
For (2), there are 5 possible values for the pair, and 5 possible values for the off-value (including 3 but not the new pair), and there are 3 dice which could hold the off-value, so there are 75 different rolls.
Hence there are 80 rolls to get Two Pair, and a probability of 80/216 = 37.0%.
Keeping the pair + 1
In this case, you're rolling 2 dice (and there are 6^2 = 36 possible rolls), and to get your Two Pair you must roll a 5 on at least one die, with the other value being anything you want. There are lots of ways to calculate this, but there are 11 ways for this to happen (e.g. 6 ways to roll 5 on the first die, plus 6 ways to roll it on the second, but subtract one because we've double-counted the roll of 55). So the probability is 11/36 = 30.5%
This makes sense, since you're saving the "progress" of having already rolled one of the needed pairs (just as in the second option), but you're also restricting yourself to only allowing one possible value of second pair show up.

I found this article helpful in understanding your calculations: https://www.datagenetics.com/blog/january42012/

"there are 5 possible values for the pair, and 5 possible values for the off-value (including 3 but not the new pair" No, once you choose one of them, there are 4 for the other. "This makes sense" No, that doesn't make sense. If you roll an extra die, it can either come up 3 (which is bad), or come up as something that restricts your other rolls just as much as saving one of the dice. For instance, if the die comes up 2, that restricts you as much as if you had saved a 2. So saving a die can't possibly make your chances worse.

@Acccumulation I definitely have messed something up in my calculations, I will try to re-do them more thoroughly (I admit I was typing this up rather quickly at the time).

Shouldn't "Keeping the pair +1" have slightly higher odds? You could also roll a pair with the 2 dice: 11, 22, 44 or 66, which would all also work to form two pairs together with the already picked 33.


text:
What effects can modify mana abilities and be affected by Mana Relfection and Nyxbloom Ancient?
Considering the following:

Mana abilities come in two forms, Activated and Triggered
Nyxbloom Ancient/Mana Reflection only works with Activated abilities of a permanent being tapped
Triggered abilities like Utopia Sprawl and Nikya of the Old Ways don't work with this ability.
Abilities that tap other permanents like Urza, Lord High Artificer or Heritage Druid are mana abilities that tap permanents but do not get multiplied with Nyxbloom Ancient*
Effects like Liliana of the Dark Realms making swamps tap for BBBB get multiplied by Nyxbloom Ancient add another mana ability but do not modify the abilities the land has.

Similar to the way Winding Constrictor does X counters + 1, versus Doubling Season X * 2, are there any effects that modify the amount of mana produced by a source, aside from the mentioned Nyxbloom Ancient and Mana Relfection?
Based off this question.

Liliana's emblem doesn't create a replacement effect. It just grants swamps another ability that produces more mana.

@murgatroid99 Liliana's emblem not being a replacement effect is a relevant distinction. I've edited the post.

Mana Reflection and Nyxbloom Ancient are the only cards that increase the amount of mana produced by other mana abilities. Some cards decrease the amount of mana produced.
In order for one card to modify the result of an ability on another card, it would need to use a replacement effect, which would contain the word "instead". So, we can look for cards with this effect by searching for cards with the words "mana", "produce", and "instead". Of the cards we find there, only Mana Reflection and Nyxbloom Ancient increase the amount of mana produced, and Contamination and Damping Sphere decrease the amount of mana produced, and change its type.


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Whom is a player bankrupt to if a Chance card tells him to pay $50 to each player and he can't pay?
If a player draws the Chance card (US standard edition) that tells him "You have been elected Chairman of the Board. Pay each player $50", and his cash is insufficient (even after he sells hotels/houses and/or trade/mortgages properties), then whom is he bankrupt to? To whom must he hand over his remaining assets?

There are indeed no instructions in the official rules on how to resolve multiple payments. A common mechanism in game design to handle such cases is to pay your debts in turn order. You go bankrupt to the player who you cannot pay.
Example: turn order is Alice, Bob, Charlie, Daniel and Eve. It's Alice's turn and she is instructed to pay $50 to each player. Her entire liquid assets are $149. She pays $50 to Bob and Charlie, respectively, but since she's $1 short of paying the debt to Daniel, she goes immediately bankrupt and turns all her assets to Daniel. Eve gets nothing.
Turn order is clockwise, as indicated by the rules:

THE PLAY... [...] After you have completed your play, the turn passes to the left.

Well, an interesting solution. But the distributuon of assets is not equal to every player, whereas the original debt is equal to each player.

The assets are sold off and divided equally among the other players
This actually situation occurred in a Monopoly Tournement
"Phil Orbanes, who wrote The MONOPOLY Companion and is the official Judge at the World Championships provided me with this answer when it came up in tournament play a few months ago:

If you cannot pay a debt to ONE player due to a card, you go bankrupt to that player and turn over all asset  (std. procedure here).
If you cannot pay a debt to TWO or MORE players (after calculating any money you could get from the bank by mortgaging and selling houses) due to a card, you go bankrupt to them all.  The issue then becomes: fairness. How do you divide your assets as evenly as possible?
Procedure: after selling any houses for 1/2 price to the bank, the bank then rebuys your properties at face value if unmortaged, or for 1/2 value if mortgaged.   You divide the resulting cash as evenly as possible, with the player(s) to your left collecting any odd dollar(s). The bank then auctions all properties it purchased to the highest bidders."

Source : Quora.com : Kevin Tostado, Director of "Under the Boardwalk: The MONOPOLY Story." MonopolyDocumentary.com
Conclusion.
The players may get a lot more than the 50$ that they were originally owed.

It seems unlikely that players would get much more than the original debt of $50, as if a player has $500 worth of property, and owes $200, he should be able to raise $200 by selling the property to other players, rather than to the bank. In fact, if I was handling this situation, I'd cap the amount players could receive at $50 each anyway, and have the bank keep the surplus.

@Pelotas : Assume that all of the player's properties are mortgaged. Then, it is to the other players' advantage to let that player go bankrupt and leave the game - that's the only objective of the game. All the  mortgaged properties will be bought at half-price by the bank and that money will be redistributed to the creditors; that sale would probably represent more than 150$. Also, the repossessed properties will auctioned off by the bank.

My play group treat this as being bankrupt while owing the Bank.
The reason for this is that the player collectively owes every player $50. If the whole collective cannot be payed then the player is bankrupt owing everyone.  There is no way to equally distribute the assets so handle the redistribution by Auction.
We don't pay the other players the $50.  The only effect is that the Bankrupt player is removed and the new auction occurs.

Why "owing the bank" if the debt is to the players? 2. This doesn't answer the question "to whom must he hands over his remaining assets?"

@JBentley It does answer it indeed.  You are not owing a single player therefore you can't distribute assets to a single player.  Handle the redistribution by auction, same as if the player had gone bankrupt owing the bank.

You didn't put that in the answer...

How if the Bank takes over both the assets and the debts? The assets are handed over to the Bank, but the Bank has to pay each player the $50.

@FerdinandLiem We don't pay it out.

This seems to be a reasonable interpretation where the rules are not clear.  Each other player gets M$50 from the bank, and the player is bankrupt to the bank, so all of their properties are auctioned off.  This seems the fairest solution to me.

It seems silly to have whom you go bankrupt to be dependent on the order in which you pay out the $50.  The rule described in this answer makes good sense: You go bankrupt to the bank; the bank pays out the $50 to each player; the bank takes your assets and does the auction.  Certainly it's within the spirit of Monopoly for a player to go bankrupt over a few bucks, but not to go bankrupt to one particular person when owing several players money simultaneously.

Like Leppy, I would play this situation as "the player goes bankrupt to the bank." That way, you don't have one player getting all the property just because of his/her position in the turn order when debt is "collective."
My answer differs from Leppy's insofar as I would have the bank pay $50 to each player (in this example) or otherwise satisfy the debt, so that all the players get what is owed them. In return, the bankrupt player forfeits all property to the bank (rather than to another player) and leaves. A real banker would usually be pleased with such an arrangement, to get someone's property back for small payments. A variation of the answer is that the property goes back to the bank, and the liquid assets (cash) are divided evenly between the other players (each gets more than $0, less than $50).
What goes on from here depends on what role you assign to the banker at this point. If you want a shorter, more "deterministic" game (based on the existing situation), the bank auctions off the properties one by one (although there are issues about the order of the auctions).* If you want "house rules" for a longer, more luck based game, the bank, having repossessed the bankrupt's properties, will sell them as the other players land on and buy them (or put them up for auction).
*Using the "auction" method, I would have an "order rule," either auction the properties alphabetically (Atlantic Ave. comes first, then Baltic and Boardwalk), or else from cheapest to most expensive.


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Betrayal at House on the Hill: Haunt 2: The Séance
During the Séance Haunt, the hero's summoned the Ghost and started traveling around to complete their quest.
The traitor then, attacked and killed the Hero who completed the Séance.
Does this mean the Hero's fail their quest because the Turn/Damage track can no longer progress?
The rules say, "Set up the Turn/Damage track with a plastic clip on 1. At the end of each subsequent turn of the player who completed the Séance, advance the clip to the next number on the track. You have until the start of the Turn 5 to bury the Ghost's bones."

For the heroes, there are two ways to win:

they either defeat the ghost after the traitor takes control of it, or they burry the ghost's bones after they summon it.

They have 5 turns to find and bury the bones. The track marker advances after the players turn. If that hero is dead but other hero's are alive, you just advance the marker at the time the dead hero should have had his or her turn.
So no the heroes only lose if the last one of them died.


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Is it true that all computer chess programs can be forced into a three-fold repetition draw?
Disclaimer: I know very little about chess: basically, how to put pieces on the board, how to move them, and how to lose (I'm a pro at this). I have no idea about my Elo rating, but I guess it's in the two digits range. Thus, please be forgiving of possible blunders in my question.
One of the few things I thought to know was that today computers are stronger than humans at chess. Programs such as Stockfish, Komodo and Leela Chess Zero should be able to regularly beat GrandMasters, and even give the World Champion a hard time. However, an acquaintance who is a way better player than me,, told me that you can draw against any computer chess program just by using threefold repetition. In other words, you make your move, the chess program makes its own, you go back, the chess program does the same (??), repeat three times and voilà, you get your draw. He said he used this strategy against chess engines you can play with on the Internet, and it works.
This seems unbelievable:

Even I could write a program which doesn't fall in such a trap. Just compare the current move with the preceding one: if they're the same, increase a counter, otherwise set it to 0. When the counter gets to 2, remove this move from the list of candidate moves. In other words, never perform the same move three times. Of course, there may be cases where actually performing the same move three times could be the best strategy: in that case, just offer a draw to the human opponent. But on the average, just avoid making the same move three times consecutively.
Different chess engines also use very different algorithms (e.g., Leela Chess Zero is based on neural networks, RL, and MCTS, while Stockfish and Komodo use other approaches, including opening databases, list of hard-coded heuristics, etc.), so it seems highly unlikely that a single approach could exist which can force a draw against all existing chess engines.
A chess engine's next move doesn't obviously depend only on my (the human opponent's) current move. I guess it depends on the full move history of the current game, as well as on the estimation, done by the chess engine, of which moves are more likely to lead to victory further down the game. Why should my current move be so important for the chess engine, that it would keep repeating the same move just because I do so?

I conclude that this is "fake news", or at most a silly bug in the chess engines this acquaintance played against (maybe not a major bug, because people who play chess on the Internet probably are not interested in a cheap trick to draw against the computer, but still a bug). But definitely not something that happens when playing against the major chess engines, such as the three I mentioned initially. Am I right?

You've basically answered your own question already. You just need to be more sure of yourself.

@NotThatGuy The current board is not always enough to determine the current state of the game in chess. The rule for castling refers to past history: did the king or the relevant rook move previously? So does the rule for en passant captures: did the pawn being captured advance two squares on the immediately previous move?

I never before heard of this three fold rule, so if I was the one writing a chess bot, I would probably introduce this exact bug.

You may be interested to know that there is a dedicated Chess Stack Exchange. A question being on-topic on another Stack doesn’t make it off-topic on this one, and this question is fine here, just thought you might want to take a look at that one. (I’m not actually familiar with the Chess Stack and don’t know for certain that this question is on-topic there; it probably would be, but it’s always best to familiarize yourself with a new site’s rules before posting.)

Perhaps your acquaintance would like to share the moves with us, although I very much doubt it this sequence exists. Most opening sequences involve pawn moves, which cannot be retracted. Even the few opening moves involving knights that I know of would just provoke a pawn response from the opponent.

@BenHillier I never said he talked about opening sequences. Anyway, it's pretty clear that what he said is BS, and that there is code in reputable engines to detect threefold repetition, so that answers my question.

I would just want to point out that computer program would not just "give the World Champion a hard time". They can easily beat any player in the world, for them playing against me (or you) or Magnus Carslen (current World Champion, maybe the best chess player ever) is exactly the same.

@bznein wow really? I was told that the fact that they beat Kasparov back in the '90 doesn't mean they can beat anyone anytime. It did sound like BS, since the progress in Computer Science is super-fast, thus if a chess engine beat the World Champion a few times 20 years ago, I would have expected them to beat any human all the times now. However, the Wikipedia page is not clear about them being super-human, so I was unsure. I definitely need to change my source for chess-related factlets

@DeltaIV Yes, check for example https://en.wikipedia.org/wiki/Human%E2%80%93computer_chess_matches which states: Since that time [meaning 2005/2006], chess programs running on commercial hardware—more recently including mobile phones—have been able to defeat even the strongest human players. Nowadays top players use chess engines for training, to explore new techniques. The only way to make games interesting is to play with "odds", i.e., just as an example, having the computer program playing without rooks

Not only can computer games not necessarily be forced into a draw, but some of them will go to absurd lengths to avoid a draw.  Here's a hilarious example: Rybka vs. Nakamura

Point 1 is the crucial one. Unless the coders have omitted the repetition rule altogether, then the bot will calculate its third repetition as leading to a draw. It may still choose it, but only when it calculates that no other alternative is any better - that is, that a draw is the best it can play for assuming you don't blunder. In this situation, either a draw is truly inevitable anyway, or you're throwing away the chance to play for a win by making the repetition.

It's possible that your friend has hit upon a sequence that works against a particular engine running at a particular difficulty. But this will almost certainly not generalize.
Engines can have something called a "contempt factor" which causes them to try to avoid draws if they evaluate the position as slightly negative. Whether this is present, and how large this factor is, depends on the individual engine.
Engines do know about threefold repetition, and take it into account. If the engine thinks it is winning, or losing by less than the contempt factor, it will avoid a move that results in threefold repetition, even if that might otherwise be the move it evaluates as best.
Also, strong engines will not always play the same opening. For one engine, if you start with 1.e4, the computer will play 8 different possible replies to that move, with probabilities anywhere from 49% to 2%. There's no way your friend has a line which causes the engine to repeat for all of them.

Thanks for bringing up this "contempt factor" - I'd never heard of it and it's a neat idea! On further reading it looks like it is sometimes actually used in both directions - either (as you talk about) to preferentially avoid draws under the assumption that the opponent is weaker than it, or to preferentially seek out draws under the assumption the opponent is stronger!

@BenjaminCosman Maybe OP's friend found an engine with a negative contempt factor, then? That would explain why it seems eager to repeat...

Well, first of all, going "back" is often not an option. Pretty much every opening involves pawn moves, and you can't take those back. You also can't undo captures. So clearly you'll have to do some work just to get into a situation where the computer can take its move back, let alone will.
The computer generally has a attributes that it's working towards, and it will make moves "forward" with respect to those goals, and taking a move back would be going backwards.
During the opening, one of the major goals is development, which generally involves moving pieces towards the center. The computer is going to need a good reason to move its pieces away from the center, and "I just moved my pieces back" hardly qualifies.
In the end game, the computer will be working towards moving its pawns forward, and moving your king away from the center. The first of these can't be undone, and the second can, but the computer has no reason to.

Even I could write a program which doesn't fall in such a trap. Just compare the current move with the preceding one: if they're the same, increase a counter, otherwise set it to 0.

Such a test would be of limited value. Suppose the computer assigns a score to each position equal to the probability it thinks it will win in that position, minus the probability it thinks it will lose. Presumably the computer will choose the move with the highest score. If the computer is choosing the same move over and over again, that means that it thinks that all other moves have a lower score. Since moving over and over again is drawing, that means its score is at most zero. So it thinks that every other move has a negative score, i.e. it thinks every other move will likely result in a loss. So why should it avoid the draw, when the alternative is a loss?
Now, this does assume that the computer is weighting a draw the same as a win plus a loss, i.e. it values "50% chance of a win and 50% chance of a loss" the same as "100% chance of draw", and this could indeed not be the case, and it would be rather complicated to get into when it would make sense to not weight them equally, but to first approximation, we can make this assumption.

"Pretty much every opening involves pawn moves, and you can't take those back." I'm sure you're aware of knights being able to move and then return to their starting position during the opening, but I feel obliged to point it out down here.

@user45266 I said "pretty much every opening". Moving knight back and forth is a tiny percentage of possible openings, and any decent AI is not going to be doing that.

Even if there was no rule that entering the same position was a draw, a decent chess engine would add it as a rule.
You cannot win if you keep repeating positions. For a checkmate, you must stop repeating positions at some point. So if you enter the same position a second time, limited depth evaluation of the position might tell you that the best move will lead to the same position again with a positive value, but the evaluation will be wrong: Entering the same position again and again will lead to a draw and therefore should be considered to have zero value.
Entering the same position again once can be correct: In position X, evaluation with limited depth may tell you that a is the best move and b is the second best. With moves performed and your evalution going further you find that optimal game enters the same position. At this point you should use move b, or check if doing a again then breaking the loop is better.

I want to add from experience that against weaker engines there can be a sequence of moves that will lead to a certain outcome. I remember playing Ruy-Lopez as white against an old chess engine (7 years ago) with the engine always making the same move. After a certain point, I learnt a combination of moves which made the engine resign. The important point is that the engine replied with the same sequence of moves every time. I would certainly lose against the engine if there was some randomness employed by the engine.
Perhaps your friend encountered such a sequence in the engine he played against. A nice way to search for such a sequence is to start with an opening, and then let engine play against itself. Now memorize this sequence and see the engine actually repeats the sequence (it's not too hard to program some randomness which can make thigs tricky.) You may end up getting a sequence of moves that lead to a draw or a victory every time you play.

As the other answers suggest, your acquaintance is entirely wrong and every functional chess engine (not to mention the strongest ones available) understands draws by threefold repetition.
Moreover, according to this Wikipedia article, there was a match in 2015 when Komodo played several grandmasters with odds, i.e. starting down material, and did not lose a single game, from objectively losing positions against grandmasters (instead, most of them were drawn). Here is also a video of Hikaru Nakamura, rated No. 1 in the world in Blitz chess, playing increasingly strong versions of Komodo, and then playing full-strength Komodo with odds, and even when Komodo had no pieces except knights, he could not win.
Of course, none of this can conclusively prove that no one could theoretically forcibly draw an engine, but it shows to illustrate just how vastly superior engines are to humans at chess, and also that no one is even seriously trying to play top engines at full strength without a handicap. And all those matches were years ago! Engines have improved even more since, so the general consensus seems to be that no human would have any realistic chance of drawing (let alone winning) a game against a top engine.

Only from my personal experience but in case it helps: Many chess computers and even really old portable ones can avoid the trap of 3 fold repetition. As suggested above they should only do it ( but I haven't seen one personally do it because I wouldn't let it maybe?) if it is best for them to draw. It is a basic rule of chess so no surprise they are equipped to handle it. I have tried to force a draw through repetition quite a few times over the years and not succeeded. We also need to factor in here how hard it can be to get a computer into a position... that trying to force a draw is even an option. ( with any reasonable degree of set difficulty anyway)
Extra:
I learnt to play chess using computers and still have my first one. A Hanimex 1550. ( good luck finding one haha  -  although the 1500 is still available on ebay) Pretty basic little unit but quite strong game and still works 37 years later. The way to beat this one in particular is to assume it will castle and prepare in advance. Works a treat. even works on all 8 difficulty settings.
My point here is there is a way to beat all programs. There is now amazingly good software though that I wouldn't be able to find flaws in. I do believe they are still there though.
I got cocky some years ago and went to the local chess club and asked to get beaten. after winning a couple of games they put me up against the club champion who beat me 3 times in 5 minutes....then replayed all the moves we both made from memory. He went on to point out where I had gone wrong and then told me I played like a computer. respect

re "My point here is there is a way to beat all programs.": If you're talking about all chess programs that will ever exist, Zermelo's Theorem guarantees there is an unbeatable program one could write, maybe it's forever beyond our ability and tech to write but I doubt it. If you're talking about all chess programs that exist today, there are already several (inc. AlphaZero) which are far beyond any chess master; they are still technically beatable, but certainly not by modern humans.


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(spoilers) Help! My group was playing risk legacy and the contents of the two pockets were swapped at the factory, help please!
Alright, basically, what happened is that on the second game we were able to open the pocket which says "open when a player is about to place 30+ troops on the board while they have a missle in their hand" (spoilers incoming). When we opened it, we were very confused. None of it made any sense really as the first thing we saw was the mutant faction. We got all the event cards for the mutants and bringer of nuclear fire, all the troops and everything and we were weirded out as none of it made any sense at all. We played the game normally and Sahara won.
Well we just finished game 3 and didn't open any packets or pockets that game. Afterwards, I looked for a complete list of spoilers and when I found it I saw what the 30+ troops pocket was supposed to be: Aliens. Now I checked, and we didn't break any rules. We opened the right pocket on game two, it just had the wrong stuff on it. "Open when using three missles in one combat roll" was still closed. Me and my brother decided to open it to see whether we got two mutant factions or swapped mutants and aliens. Either would've been a problem and I don't have a solution for either. What we have now is two swapped pockets. On game 2 we should have got aliens, but we have mutants, and we also already placed 3 missle powers on Die Mechaniker, Imperial Balkania and the Saharan republic. So far, the solution me and my brother have come up with is to place mutants and all their respective event cards (including the two remaining missle powers) back in the pocket they're supposed to be in, and re-open it when we actually meet it's requirements, until then we will ignore all missle powers already placed on factions.
Die mechaniker was supposed to be the alien collaborator and place his 30 troops on the alien island, but we never got around to that for the obvious reason that the contents of both pockets were swapped and we didn't catch it until after game 3. So far we haven't used any of the missle powers, but we still have the problem that one of the players in our group is hoping to gain "the bringer of nuclear fire" token next game and place the fallout territory. One of the ideas I had was to have the player who completed the objective game 2 to place the alien island at the start of game 4 and place 30 alien troops on that island with their HQ with the stipulation that nobody could play as the aliens in the fourth game. My brother disagreed. There is also the idea to just help him "re-open" the 30+ troops packet (even though the thing is already torn off) and just have it play normally, but I still don't know what to do to fix this.

We had the same issue, seems to be a common factory error?

Seems to be a common error: https://boardgamegeek.com/thread/1451620/misslabled-packets-anyone-else-have-spoiler-free


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Elevation simulation
So, I am designing a board game. In it, players will recreate various tank battles (essentially a tabletop version of War Thunder.) The tanks will be represented by 3d printed models, so its a little like a cross between Armada and Axis and Allies Miniatures.
Design is going good, but I have run up against a problem: I cannot figure out how to simulate elevation. What are some techniques I could use to do so?

Do you mean visually on the game map, or mechanically in the game rules?

@ArcanistLupus : Both.

If you can provide some of your ideas on how to represent elevation and what may be wrong with them it would improve the question in my mind.

Like Arcanist Lupus said, it depends on whether you mean simulating elevation on your board, or as a mechanic.  Here are some brief notes for either case, but I will improve the answer when you clarify your question a bit.
As far as simulating elevation visually is concerned, this can be done with a contour elevation map.  These are maps which have bands at each gradation of elevation.  Every point along a single band is exactly the same elevation, and the distance between any two bands covers the same amount of elevation.  If two bands are close to each other at a point, that indicates a steep elevation, whereas a further distance is representative of a more gradual slope.
As far as mechanics are concerned, elevation can impact movement and combat.  Some parts of your contour map could have bands which are very close together, to the point where they are too steep to be passable.  Additionally, you can have a movement penalty for increasing in elevation, or a movement boost for decreasing in elevation.  You could also add a chance for a vehicle to slide down the hill they are on if they are ascending too rapidly.  A vehicle at a higher elevation will have a longer range than one at lower elevation.  You could implement range in your combat with physical measurements (like inches or mm), and increase or decrease that range in game based on the relative elevations of your vehicle and its target.  So if you were to attack up an elevation, you would have reduced range, but attacking down elevation will increase range.


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Is it possible to convert a settler ship into a settlement without moving and then build or is it considered a move?
Is it possible to purchase a settler during the build and trade phase, then load him onto a ship, move him, and then on a next turn convert him into a settlement during build phase?
Or is it considered to be a move and can it be done only during the movement phase?
Edit:
The things I find confusing are:

Manual says: you can not build after moving phase (spend resources) with exception of converting because it does not cost resources
Manual doesn't say I can not convert during build phase
Manual says I can convert anytime when my ship points hex
Manual says I can build a ship on a hex occupied by pirate ship without paying tribute because its not moving (so why converting would be moving ?)

So based on this info I would assume that I can convert setter ship into settlement during my build phase if it is in a correct position already, and then I could upgrade and/or build other stuff.

Converting a settler to a settlement is done as part of the movement phase, and can't be done during the build and trade phase.
This restriction to the movement phase can be missed in the English version of the rules because the sectioning is somewhat unclear;
luckily we can clarify things a little using the title in the German version of the rules: bewegungsphase: siedlung mit siedlerschiff gründen or Movement phase: Establish a settlement with a settler ship.
as a general rule:

In the build and trade phase you do things for which you need
resources.
In the movement phase you do everything for which no
resources are needed (exception: buying additional movement points for wool)

Can you provide quotes from manual, on which this rules are based ? Updated the question with parts I find confusing.


text:
Does a Wizard gain treasures from a charmed monster AND flee a second monster during the same combat?
During a combat, I was first fighting a monster of level 6, that I could easily beat. Then, a player added a monster to the combat of level 18, that I couldn't successfully beat. So, as a Wizard, I was able to charm the highest monster, so he leaves his treasures in the room.
The question is; do I directly gain the left treasures within my hands after charming the monster, as stated in the Wizard card ?
However, I ended fleeing the entire combat. Do I gain the treasures left in the room still?

No. From the FAQ:

...if you use an ability to make one monster disappear, you cannot claim
levels and/or Treasures for beating it (depending on the method used)
unless you can then kill or defeat all the remaining monsters. You
cannot, for instance, use your Wizard to charm one monster and take
its Treasures before fighting the rest. Combat isn't over until the
WHOLE combat is over.

I didn't know this website. Thank you for your answer!


text:
Can a player use the Wand of Dowsing card during a combat which is not his?
During a combat I had, a player played a blue card (Wand of Dowsing) and selected a card in the pile that would cancel the combat that I was having. Is that legal ?
The "Wand of Dowsing" card states that:

Go through the discards to find any one card you want. Take that card and discard this one.

Here is the card:

Can you include the text of what the card does?

Is the card actually Wand of Dowsing?

I am playing the game in French, so I am not certain of the translation... It is "Baguette de sourcier" in French !

After some research, @LeppyR64 you were right, it is the Wand of Dowsing ! And Joe  W I added the card's content & image.

This should help you.

Q. The Wand of Dowsing doesn't say "Usable once only," but I have to discard it after I use it. Can I treat it like a one-shot (play it from my hand rather than the table, or play it during combat)?
A. The clear intent is that this is a one-shot card, even though it lacks the magical "Usable once only" language, and so the rules of one-shot cards apply to this one as well. It can be played during combat, and it can be used from the hand. We've fixed this error in recent printings.

Source: Munchkin FAQ


text:
Why are there so many easily avoidable game changing translation errors in Dominion?
(This question is for people who have knowledge about the process of game translation.)
In Dominion each card (and event, landmark, project, ...) has some text on it explaining what it does and to what and how it reacts.
The original language of the game is english but I am german so I have the german translations of Dominion.
What I noticed when I read the cards and the corresponding Dominion Strategy Wiki pages was that some cards have got some slight but game changing alterations when they were translated.
Like a card which can attack other players if you choose one of two options, but in the german translation it attacks every time no matter the choice you made (Minion).
There is even a whole page dedicated to (german) translation errors in Dominion: Übersetzungsfehler.
The page also lists fixes for each translation error and you can see how easy it would have been to fix them (in a review for example).
I always thought that people who translate games must be super sensitive when they translate rules (as opposed to the lore of a game) in order to avoid alterations to a carefully balanced and play tested game.
So my question is: Why are there so many easily avoidable game changing translation errors in Dominion?

Clearifications:
A comment pointed out that translations are hard. My question can be understood as: Why is the translation so hard so that so easily avoidable mistakes happen?
Also I don't know how big of a problem this is for other games so I asked specifically about Dominion.

Without an answer from the manufacturer, any answer will be speculative. But I assume they used a translator without the required experience.
But I like the fact, that the community provides us with a fix.
Also I always try to get the game in the original language because the translations usually suck. The only exception I know of is the dutch translation of Munchkin, which has a few jewels.

Translations can be hard and have caused problems for even major international companies

I hope for an answer of someone who has some knowledge about the process of game translation

@JoeW yeah, but why is it hard? That is my question: why is the translation so hard so that so easily avoidable mistakes happen?

If that was easily answerable would all these companies have these problems?

I do not know if all companies have these problems that is why I asked specifically about Dominion. Also even though a problem can easily be spotted doesn't mean it can easily be fixed.

closed as opinion-based? why though? the answer clearly shows that this question can be answered ... or at least comment some hints on how I can improve this question ...

Sorry that this is not strictly an answer to the question, but it is too long to be a comment and it does give some information about where to find more.
From the late 1990s to the mid 2010s I was a frequent participant in the Spielbox discussion forum. During that time we had a couple of threads about that topic. This is a link to the oldest one from the archive (the site has since then moved to a new URL, but old threads are archived): Eurogames-Spiele nicht mehr kaufen.
Unfortunately the search engine will ignore "dominion" because of too many hits :-(
If you search for "Übersetzung" and restrict it to "Nur im ersten Beitrag der Themen", you will get 207 hits in the Archiv of Spieleforum. Several of them are specific to issues in one particular game, but often some people with insight (working for the publisher or translators) gave answers.
What I do remember from those discussions was different publishers have different approaches - some hire professional translators (sometimes translators with little or no ties to gaming, which is considered a big problem in the gaming comunity, because they lack the knowledge of particular or usual gaming terminology), sometimes games are translated by gamers with good English knowledge.
On a few occasions some of the latter stated something like:

I just got a pdf of the original language rules and had one(!) week to translate it. I didn't even get a copy of the game so that I could have played it at least once as I would have preferred. I know that the translation is not good, but it is the best that was possible under these circumstances

So if there is a short answer to your question, it is quite trivial: time pressure.


text:
Smallworld Sorcerer abilities explained
Played Smallworld for the first time today. My son played as the Sorcerers and we couldn't figure out exactly how to interpret his abilities, even after reading the rules.
It says that the Sorcerer's abilities are, for each opponent, they get to replace 1 of the opponent's tiles for a Sorcerer. Sounds simple, right? Well, pretend I'm the Trolls.
What if I have a Troll region with 5 Troll tiles on it? Well he puts down 1 Sorcerer tile on that region and takes away 1 Troll. Now that region has 1 Sorcerer and 4 Trolls on it.

Who gets the coins for that region at the end of their turn? The Sorcerers or the Trolls, both, neither?
Can my 4 Trolls now attack his 1 Sorcerer on that region?
Can he, at the end of his turn, deploy more Sorcerers to the region?

I couldn't find anywhere in the rules where this was covered. Thanks for any and all help!

You missed an important part of the sorcerer rules: they can only use their power on a region that contains just a single opponent piece. From the rulebook:

The token your Sorcerers replaces must be the only race token in its Region (A single Troll token with its Troll's Lair is considered alone for this purpose; likewise for a Race token in a Fortress or on a Mountain, these markers provide no protection to a lone Race token) and that Region must be adjacent to one of your Sorcerers'.

So all your questions don’t really apply, because the sorcerer’s ability cannot create a region with 2 different races in it. After using its power, there will be a single sorcerer token in the region, and the region will belong to the sorcerers like any other region they have.

Note that this does make Sorcerers good against Trolls (or Bivouac, or Bivouac Trolls on a mountain space!) as the extra defense is negated. Only the number of creature tokens matter for the Sorcerers abilities. But remember to remove the lairs or other bonus tokens afterwards. Sorcerers don't get to keep them.


text:
Once-each-turn Abilities with Controller Changes
Quirion Ranger has an ability with the restriction :"Activate only once each turn".
If the ability is activated, then later on the same turn control of the Ranger changes, can the new controller activate the ability?
Is the answer any different for Mairsil, the Pretender's ability; "...You may activate each of those abilities only once each turn."?
EDIT: on rereading the last ability of Mairsil, only the owner of the exiled cards can activate their abilities, so that question is moot.

Rule 602.5b:

If an activated ability has a restriction on its use (for example, “Activate only once each turn”), the restriction continues to apply to that object even if its controller changes.


text:
How closely must clues relate to the keywords?
My friend and I got into quite a heated discussion about which words are allowed to be used as clues, the disagreement was in the interpretation of the rule (emphasis mine):

The Clues must refer to the meaning of the Keywords. The Clues
must never refer to the spelling (“C” to hint at “Cursed”), the number
of letters(“8” or “8 letters” to hint at “Scorpion”), the position on
the Screen (“musketeers” to hint at the word in the third position),
or pronunciation (“face” to make your team guess “Place”).

Decrypto English Rules
I understood the part in bold to be in contrast to the rest of it, that the encryptor must be thinking of the meaning of the word, not the spelling, number of letters, position, or pronunciation. But the clue can be stretched as far as you like, and take multiple steps to guess the keyword, at the risk that your own teammates might not make the connection.
My friend understood it to mean that the clue must be closely related to the meaning of the word. That is, the clue is not allowed to refer to something else, which can then be related to the keyword. He said, in terms of 'relatedness', there is a sweet spot for clues. One where it is not too closely related to be too easy, yet not too far removed that it becomes illegal.
My main concern with that interpretation is that there is no objective way to evaluate whether a clue is legal.
My friend's objection to my interpretation is that it can make it impossible for the opponent to intercept the messages.
What is the intention of the quoted rule, namely the emphasised bit?
Examples

"Generally" as a clue for "Army"

My friend said "General" would have been fine. But since it's using a bit of wordplay to step from "Generally" to "General", it violates the spelling/pronunciation rule.

"Sea" as a clue for "Army"

This is an example of multiple steps. "Sea" relates to "Navy", which relates to "Army". "Sea" and "Army" don't relate. I think that is legal, my friend thought the degree of separation is too far, since the clue does not directly refer to the meaning.

"Default Skin" as a clue for "Job"

My teammate and I both enjoy Minecraft, in which the default skin is named "Steve", and "Steve Jobs" makes the connection to the keyword. I thought it was a brilliant (and legal) clue, but my friend argued that "Default Skin" does not refer to the meaning of "Job". Also, since the common "Steve" part is different in meaning in both cases, it's a bigger stretch.

I didn't find any official rulings, but here are my 2 cents.
Any clue you give as the Clue Giver that you can connect back to the keyword is valid. The end goal is for your team to correctly guess the code while keeping the opposing team from guessing your keywords. You do not need to justify your clues to the opposing team. If your team is also not getting the clues, you may need to rethink the wordplay and clue complexity.
Let's take a look at your examples:

"Generally" as a clue for "Army"

I don't see this as a clue that breaks any rules.

My friend said "General" would have been fine.

Both you and your friend are correct. Which clue is "better" depends on how well you know your team and the opposing team. I think that "Generally" is a better clue than "General" since it adds another level of vagueness. While "General" is also a good clue, this may be too obviously connected to Army, and it's not too far removed from "Generally".

"Sea" as a clue for "Army"

Again, this is a valid clue. Depending on the other keywords available, it's hard to say if this is a "good" clue.

"Default Skin" as a clue for "Job"

I think this clue will depend on the players. It's not a clue I would use when playing with a random group, but if I knew someone on my team would understand the reference, then it's something I would use.

I think all of these clues are valid. It's unclear if the "friend" is on your team or the opposing team, which may change this answer. The entire point of the game is using logic to relate a group of words to one specific keyword.
The further away a clue is from the keyword, the higher the chance of a Miscommunication. The closer a clue is to the keyword, the higher the chance of an Interception. It's up to the Clue Giver to find that sweet spot based on the players. This game has no tournament rules; it's meant to be light, loose, and fun.


text:
When a card instructs an opponent to do something, how does that work in a multi-player game?
Using Demonic Hordes as an example, since that's the card that made me think of this.
If I have two opponents and don't pay the upkeep cost, who gets to choose which land I sacrifice? Is it simply the next player in turn/APNAP order? I can't imagine what else it would be, but is there a specific section in the comprehensive rules where this is explicitly stated?

You choose an opponent. That opponent chooses a land for you to sacrifice.

At the beginning of your upkeep, unless you pay BlackBlackBlack, tap Demonic Hordes and sacrifice a land of an opponent's choice.

(You may choose a different opponent each upkeep that you do not pay BlackBlackBlack.)
From a 1995 ruling:

Choose a different opponent each time the effect applies.

(That link has a long list of such rulings for the cards that were available at the time)
For a more recent rules compilation, see
https://mtg.gamepedia.com/Multiplayer
According to the comments, theses are now in section 601.5a

interesting, is there anything in the comprehensive rules that helps with this? It seems like the rulings vary wildly for how to handle it! I can only imagine that there have been a lot more cards since 1995 that instruct and opponent to do something; are every one of them governed by arbitrary rulings in multiplayer games?

Well, it's not exactly arbitrary. Every instance of "opponent" is either "target opponent" (i.e., you choose, or the one you had previously chosen), or, for wide effects, "all opponents". Which is which is usually obvious. But see this for more: https://mtg.gamepedia.com/Multiplayer

For a related question: https://boardgames.stackexchange.com/questions/23587/when-an-opponent-has-to-do-something-in-a-multiplayer-game-who-does-it#:~:text=1%20Answer&text=The%20player%20who%20controls%20the,you%20because%20you%20were%20friends.  The relevant rule is 601.3a "If there is more than one opponent who could make such a choice, the spell’s controller decides which of those opponents will make the choice."

@L.ScottJohnson [mtg: Captive Audience] says "Captive Audience enters the battlefield under the control of an opponent of your choice." That's different from "target opponent"; if it says "target opponent", you can't use it on an opponent with hexproof.

The card wording and oracle wording are subtly different. The card says

Pay BBB during your upkeep or the Hordes becomes tapped and you lose a land of opponent's choice.

The oracle wording says

At the beginning of your upkeep, unless you pay BBB, tap Demonic Hordes and sacrifice a land of an opponent's choice.

So according to the Oracle wording, you sacrifice a land of an opponent's choice. Now, I don't know if the MtG rules explicitly say "When an effect that you control refers to an object or players when more than one would be valid, you choose which one it refers to", I think it falls under common sense. If a card says "Sacrifice a permanent you control", it means "Sacrifice a permanent you control of your choice". While my cursory search of the rules didn't find that particular principle articulated, it did find this:

602.3. Some abilities specify that one of their controller’s opponents does something the controller
would normally do while it’s being activated, such as choose a mode or choose targets. In these
cases, the opponent does so when the ability’s controller normally would do so.
602.3a If there is more than one opponent who could make such a choice, the ability’s controller
decides which of those opponents will make the choice.

Normally, when you are instructed to sacrifice a land, you can choose which land to sacrifice. Here you are being told to allow an opponent to choose, so 602.3a tells you that you can choose which opponent will make the choice.

@Andrew ? That doesn't explicitly say exactly what I was talking about (which is that in general, when there are more than one possibility, the controller chooses). I cited the rule for abilities that says that about players. You cited the rule for spells, but it's Demonic Hordes' ability that is being discussed, not a spell.


text:
Which game is this die with a tornado or spiral on half its sides from?
Please identify the game this die (shown in the picture below) comes from.
The die has 3 blank faces, and this tornado (or spring?) design on the other 3 faces.
I don't have any other information. The die came with a different game bought at a thrift store, but does not belong.

Besides Fate (+,-, empty) and the Fantasy Flight Games, I know no game with special dice, and that is neither of those.

Can you edit in a more clear and zoomed in photo? It is kinda hard to see the exact details of the tornado.


text:
Can I use Ulalek's ability multiple times after casting a single spell?
So my friends and I were talking about Ulalek, Fused Atrocity, the new Commander for the Eldrazi pre-con deck, and I wanted to know if the ability can be paid for more than once on just any instance. For example if I was to cast Ulamog, which has a cast trigger, could I pay two colorless however many times I want to trigger the same cast trigger or is it once per cast?

This is slightly tangential to your question, but copying a spell will not trigger any on-cast triggered abilities again, since you don't cast the copy.

@MatthewJensen Ulalek does copy triggers on the stack in addition to spells, so the on cast triggers will still get an additional. copy put on stack.

Extort would be OP if this were how it worked.

@Andrew Yes, but the copy of the trigger is from Ulalek. The copy doesn't put additional triggers on the stck.

You can pay once for each spell you cast.
Ulalek's ability is a triggered ability. When you cast an Eldrazi spell, the ability goes on the stack. Once the ability resolves, it gives you one opportunity to pay {C}{C}, and if you do, it copies each other spell and ability on the stack once.

You would need Echoes of Eternity out to do what you are asking. That would make a loop with Ulalek to pay for his ability as many times as you can afford it. You could also add things like Annie Joins Up, Strionic Resonator, or Roaming Throne to double up on his ability while still having to pay the two colorless for each time the trigger is doubled


text:
Mtg: Electrostatic Field return to hand
Situation:
The Electrostatic Field is a creature.
In my turn I play the Artful Maneuver.
My opponent plays the Compelling Deterrence and returns the electrostatic field in my hand.
I know that his spell is over my spell in the stack, but is the ability of the electrostatic field still triggerd or not because it returns to my hand before my spell is spoken?
In the ruling on gathering.wizards is said:
Electrostatic Field's triggered ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
But it’s not a counter spell to the spell it brings the creature back in my hand.

Although the linked question may give the answer in this case, I don't think it's quite a duplicate because of the wording in the question "is the ability of the electrostatic field still triggerd or not". That implies that either it's not clear to the asker that it would already have triggered, or that the asker thinks that being triggered is an ongoing state rather than a one-time event.

Standard terminology is that things are "on top" or "above" other things in the stack. Maybe it's just me, but it took me a few moments to parse the term "over". And spells "resolve", not "are spoken". While from the context, I can infer what you mean, this question relies quite heavily on the distinction between a spell being cast versus resolving, and the term "spoken" is extremely unclear as to what it means.

Electrostatic Field's triggered ability is triggered before your opponent ever casts Compelling Deterrence. An ability triggering is a thing that happens at a specific moment, abilities are not "still triggered" later on.

Casting Spells

601.2i Once the steps described in 601.2a–h are completed, effects that modify the characteristics of the spell as it’s cast are applied, then the spell becomes cast. Any abilities that trigger when a spell is cast or put onto the stack trigger at this time. If the spell’s controller had priority before casting it, they get priority.

So as soon as you finished casting Artful Maneuver, the ability triggered, and then went on the stack above Artful Maneuver, before your opponent had a chance to cast his spell. And as per the linked question, once that ability is on the stack, Electrostatic Field is no longer relevant.

113.7a Once activated or triggered, an ability exists on the stack independently of its source. Destruction or removal of the source after that time won’t affect the ability.


text:
Multiple End step events
Let’s say I have Promise of Tomorrow and a couple creatures exiled with it. I cast Eerie Interlude during my main phase and exile all my creatures.
Now, what I want to know is if Promise of Tomorrow’s ability will be triggered since technically, going into my end step, I don’t control creatures, even though the ones I exiled with Eerie Interlude should come back at the same time as Promise of Tomorrow is supposed to trigger. Any ideas?

Depends on what order you put the abilities on the stack.
You will have two triggered abilities that trigger at your end step. The Promise of Tomorrow checks for creatures when it triggers and when it tries to resolve.
Seeing as there are two triggered abilities that you control that are trying to go on the stack at the same time. You can choose their order. Remember mtg is still a turned based game. Things can trigger at the same time, but they still resolve one at a time.
If you put Promise of Tomorrow ability on the stack and the Eerie Interlude on top of it. The Eerie Interlude will resolve first and when the Promise of Tomorrow tries to resolve it will see creatures and nothing will happen.
If you put the Eerie Interlude on the stack with the Promise of Tomorrow on top of it. The Promise of Tomorrow will see no creatures and resolve and then the Eerie Interlude will return creatures from exile as normal.
The stack in mtg just like the stack in computer science is a first-in-last-out concept.
The intervening IF clause
Rule 603.4 from the Magic Comp Rules - source

A triggered ability may read “When/Whenever/At [trigger event], if
[condition], [effect].” When the trigger event occurs, the ability
checks whether the stated condition is true. The ability triggers only
if it is; otherwise it does nothing. If the ability triggers, it
checks the stated condition again as it resolves. If the condition
isn’t true at that time, the ability is removed from the stack and
does nothing. Note that this mirrors the check for legal targets. This
rule is referred to as the “intervening ‘if’ clause” rule. (The word
“if” has only its normal English meaning anywhere else in the text of
a card; this rule only applies to an “if” that immediately follows a
trigger condition.)

Excellent answer, but it could be improved by adding a reference to rule 603.4, the "intervening 'if'" rule


text:
Can Mewto and Mew Tag Team GX's Perfection ability be prevented from using by using Golduck's amnesia attack?

In Pokemon tcg, I got a card named "Mewto and Mew GX", and the "Perfection" ability looks cool. But when I put it into combat, I encountered a problem. For example, golduck's attack amnesia does 20 damage and chooses an attack from the defending pokemon, and that pokemon cannot use that attack during the next turn. So, what if golduck faced Mewto and Mew GX? Can golduck prevent Mewto and Mex from using the ability, or is it that because it's an ability, "Perfection" cannot be prevented from using during the next turn? I'm quite confused so someone pls help me!

BTW, Golduck is from Team Up and Mewto and Mex GX is from Unified Minds.

Perfection is an ability. Abiliteas are different and distinct from attacks.
So Golducks Amnesia Attack cannot prevent the use of the perfection ability since it instructs to choose an attack to prevent.
From the game rules:

ABILITY: An Ability is an effect on a Pokémon that is not an attack. Some will be active all of the time, while some you will need to choose to use. Read each Ability to make sure you understand exactly how and when it works.

The Amnesia attack also says to choose one of the defending pokemons attacks, the only choice here is Miracuolous Duo GX, since the attacks that MewTwo & Mew GX gets from perfection are not it's attacks but the attacks of the other benched pokemon.


text:
Woogles puzzle: Why is K9 WILL significantly better than 2M WOE?
I'm confused.  I did the Woogles.io puzzle:

I played 2M WOE which scores 34 points, but the answer is K9 WILL which scores 28 points.  The Woogles.io analysis bot indeed prefers WILL, despite it scoring less:

That seems like a big difference.  I'm fairly new to Scrabble, so I'm not sure what the big idea here is.  I'm guessing it's because the leave of NRO (after playing WILL) is better than the leave of LLRNI (after playing (WOE).
Question: Why is K9 WILL significantly better than 2M WOE?

@Allure Current score usually not all that relevant in mid-game, only near the very end.

@Allure I wouldn't be worried about that type of strategy in mid-game, only towards the end. But everyone has their own way of playing.

The problem is definitely the leave. Ls are a pain, two of them doubly so. They are relatively hard to use. The rest of the letters - NRO or NRI - are essentially the same, so ending up with 4 new letters instead of two letters and not having the Ls any more gives you much better odds for the next move.
It is also not purely about point values. Yes, giving up more one point tiles gives you a higher average point value for your replacement tiles. But there are points and there are points. I'd gladly keep two Ts over two Ls. On higher point letters, I much prefer an M or a P to a C (all 3 points) and an F, H, W or Y to a V (all 4 points).
Look at it another way - NRO gives you a decent chance at a Bingo. LLNRI does not.

100% agree with this. It's all about the leave. Only small comment: sometimes a V can be a better bingo tile than, say F or W, because of suffixes like -IVE . . . though in general you are right V is awful :^P

It isn't that V can't be a useful letter. But in general F and W are better because of things like this situation, where W gets used in both directions - doesn't happen so much with a V.

Yes, not appearing in any two letter words is the main reason why V is bad, same with C. Though they are decent bingo tiles.

@qdread Yeah, it is possible to UNCOVER some decent moves.

@Allure Impossible to say for sure without the new letters. But there is an R which makes a good start for a lot of words at D14

The big difference is how valuable the tiles you are left with is, how valuable the replacement tiles should be, and how likely you are to be able to use them better on your next turn.
The average point value for a scrabble tile is 2.87. Your tiles are worth 10 points (1.43 Average). WILL gets rid of 4 tiles worth 7 points (1.75 average) leaving you with 3 tiles average value 1, for an expected average on your next turn of 2.07 for your tiles. WO(E) gets rid of 2 tiles worth 5 points (2.5 average) leaving you with 5 tiles average value 1, for an expected average on your next turn of 1.53 for your tiles. Both also leave you with one vowel, but drawing 4 tiles off WILL makes you much more likely to be able to draw a second vowel, making it more likely to have better play options for your next turn.
It's not always about what scores the most points now, it's about what gives you the best chance over the whole game, playing longer words, drawing more tiles, and having a better set of tiles for the next turn is important too.


text:
Is it legal to make trade deals before using a monopoly card?
For example - Suppose there are 12 Ore cards in circulation, and I hold 3.
On my turn, can I trade those there ore cards with someone else for some wood and then use a monopoly on ore to regain all those ores back?
Effectively I have received that wood for free from the other player.

It's a really good tactic - I know several people that use that effectively.

So it's legal then? I used it yesterday, and it felt horrible, in addition to the disapproving stares by the other players.

That's why it is a comment and not an answer - I have no idea if it is legal but I assume so because the person I know is a rules stickler.

A tactic being legal and doesn't mean it is something you should use in a game.

@JoeW This is entirely customary for the Monopoly card. It's why players should be cautious of one player making an enthusiastic attempt to trade away lots of a single resource.

@chrylis-onstrike- That depends on your group in some groups it is not welcome at all.

Related: https://boardgames.stackexchange.com/questions/577/is-pretending-to-want-to-trade-before-playing-a-monopoly-card-objectionable

This is a perfectly legal, and quite common tactic.
The Monopoly card has no play restrictions other than the typical "once per turn, not on the turn you got it" Dev card restrictions. It affects all resources of the named type in play, regardless of how long the other players have owned those resources.  Trading resources away and then Monopolizing them back is therefore perfectly legal because there is no rule against it.
There is a cost in player interaction, though
If the other players feel that you've taken advantage of them, they may stop trading with you.  Whether this cost is enough to make you skip this tactic depends on where you are in the game. Trading typically drops off near the end anyways, as it becomes obvious that trading with the lead player will help them win more than it will help you catch up.  Stealing their resources with bad faith trades merely runs the risk of cutting off your trades sooner rather than later.
Of course, if the other players really feel that this tactic is unsportsmanlike, they may stop playing Catan with you. Some players don't enjoy aggressive play styles, and playing aggressively is incompatible with playing with them.   This is going to vary depending on the social contact of each specific game group (some players will dramatically declare unending revenge if you pull this on them, but consider it part of the game and would happily do these same to you, while others are genuinely bothered by it) and is something you will have to judge for yourself.

Good last paragraph. The difference in play styles can be incredibly varied. Things that are perfectly acceptable at one table will get you all but banned at another.