Hostage Chess Preset for Game Courier

Invented by John Leslie, Hostage Chess is a hybrid of Chess and Shogi that can be played with a single Chess set. As in Shogi, pieces may be dropped back on the board. But instead of converting pieces to your side when you capture them, you just hold them hostage until you can exchange them for your own captured pieces, which you may then drop on the board. This preset for Hostage Chess enforces the rules, spots check, checkmate, and stalemate, automates captures, and provides you with special operators for exchanges and drops.