Consider a game in which three players must decide how much to contribute to fund a holiday party. Each player i ∈ {1, 2, 3} selects a contribution level xi ∈ [0, 2] at personal cost x 2 i . The party yields to each player a benefit of x1 +x2 +x3 +x1x2x3. This, player is payoff is x1 + x2 + x3 + x1x2x3 − x 2 i .