Cyvasse is originally a fictional two-players game in George R.R. Martin's A Song of Ice and Fire series; he described it as "a bit of chess, a bit of blitzkrieg, a bit of stratego. Mix well and add imagination." This fan-made implementation by Alex McRitchie is played on a hexagonal board and features 10 different playing pieces, including cavalry units, ranged units (a catapult, a trebuchet and crossbowmen), and special units such as dragon, war elephants and mountains. Like in Stratego, before game starts players secretly place their units on the board, using a screen. Each unit can only capture units that are as strong as it or weaker, except that some units can "trump" stronger units: a trebuchet is the only unit that can kill a dragon. Many units have unique powers, like the ability to move twice or to attack from a distance.