def n_interactions(nplayers, repetitions):
    """
    The number of interactions between n players

    Parameters
    ----------
    nplayers : integer
        The number of players in the tournament.
    repetitions : integer
        The number of repetitions in the tournament.

    Returns
    -------
    integer
        The number of interactions between players excluding self-interactions.
    """
    return repetitions * (nplayers - 1)