  Creating and evaluating games manually is an arduous and laborious task.
Procedural content generation can aid by creating game artifacts, but usually
not an entire game. Evolutionary game design, which combines evolutionary
algorithms with automated playtesting, has been used to create novel board
games with simple equipment; however, the original approach does not include
complex tabletop games with dice, cards, and maps. This work proposes an
extension of the approach for tabletop games, evaluating the process by
generating variants of Risk, a military strategy game where players must
conquer map territories to win. We achieved this using a genetic algorithm to
evolve the chosen parameters, as well as a rules-based agent to test the games
and a variety of quality criteria to evaluate the new variations generated. Our
results show the creation of new variations of the original game with smaller
maps, resulting in shorter matches. Also, the variants produce more balanced
matches, maintaining the usual drama. We also identified limitations in the
process, where, in many cases, where the objective function was correctly
pursued, but the generated games were nearly trivial. This work paves the way
towards promising research regarding the use of evolutionary game design beyond
classic board games.
