Gemfire (released in Japan as Royal Blood or ロイヤルブラッド Roiyaru Buraddo, Super Royal Blood or スーパーロイヤルブラッド Sūpā Roiyaru Buraddo in its Super Famicom version) is a medieval war game for the MSX, Nintendo Entertainment System, Super NES, FM Towns, Mega Drive/Genesis, MS-DOS, and later Windows, developed by Koei. The object in the game is to unify a fictional island by force. Players use soldiers and knights, as well as fantasy units such as magicians, dragons or gargoyles in order to capture the castle needed to control that particular territory. A sequel, Royal Blood II, was released in the Japan market for Japanese Windows.