Colonel Blotto's Tug of War

We examine Tug of War contests with the Blotto specification. Players have fixed effort budgets and must allocate these budgets to a sequence of battles. The outcome of each battle is a function of the efforts allocated to that battle. The player who first wins L more battles than the opponent wins the contest. We prove the one-step deviation principle for the undiscounted version of this game. We then derive a pure strategy, subgame perfect equilibrium for the case where the contest success function that governs each battle is a generalized Tullock function with exponent 1/2 or less. In the equilibrium, the players invest the same percentage of their remaining resources into each battle. The value of this percentage depends on how close each player is to winning the contest. Escalation of efforts, measured in relation to the players' remaining budgets, occurs when the player with the smaller budget is close to winning. At the same time, the probability that a player wins any individual battle remains constant along the entire equilibrium path.