Leif D. White

Date of Award


Document Type


Degree Name

Master of Science


Department of Electrical and Computer Engineering

First Advisor

David W. King, PhD


To take most advantage of collaboration, negotiation is paramount to succeed in press Diplomacy. Humans use this construct to work towards self victory or sometimes towards an alternative strategic objective undefined in the game’s rules. To emulate this behavior, this thesis examines how to use communication to enable the victory or defeat of any other player in the game. This research develops a press Diplomacy agent, Lyre, that can work to attain these specific objectives in Diplomacy through the regret matching algorithm (RM). We also study how Lyre can begin Diplomacy with the goal to win, then shift strategies to support a different power once its believes victory is infeasible - emulating the human “kingmaking” behavior. Our results indicate Lyre’s success against pre-existing baselines and against alternatives to RM at achieving personal victory or completion of alternative strategic objectives. This shows the utility of RM and the potential for Diplomacy as a serious game to practice wargaming in an environment with unpredictable opponents.

AFIT Designator



Approved for public release: 88ABW-2023-0201

A 12-month embargo was observed.