A chess variant where getting attacked wins.
UnCheck Chess is a focused, offline chess experiment built around two ways to play:
• NORMAL CHESS — checkmate your opponent to win. The ordinary game.
• UNCHECK CHESS — begin your turn with your king attacked to win. Kings may enter attack and captures are compulsory. Expose your king, then force your opponent to leave at least one attack in place.
Kings are never captured. Castling may cross attacked squares. A player with no permitted move draws, and ordinary insufficient-material draws are disabled in Uncheck.
Two neural networks are waiting:
• SAGE — its original normal-chess champion weights, unchanged
• JESTER — an active UnCheck training snapshot, continued from the earlier Jester model
Pick a model and a ruleset. Sage uses its highest ranking in Normal and lowest in Uncheck. Jester uses its highest ranking in Uncheck and lowest in Normal. Each model keeps one bundled set of weights while the selected rules determine legal moves and winners.
Then choose how hard it thinks:
• LOW — the policy head alone: one pass, no lookahead
• MEDIUM — a 100-position tree search
• HIGH — a 400-position tree search
Both models run entirely on your device. No connection or account is required.
WHY IT IS DIFFERENT
Most chess apps ask how strong a bot can be. This one asks what a network learns when the goal is turned inside out, then puts you in the same variant so you have to beat it there.
Sage and Jester are neural chess models, not perfect oracles. A model's lowest-rated move can still be dangerous, or simply strange. That uncertainty is the experiment.
BUILT FOR A QUICK GAME
• Play as White or Black
• Tap any highlighted legal destination
• See every compulsory capture source in gold and target in red
• Choose every promotion piece
• Review the game with forward and back history controls
• Keep reviewing the board after the result, with the winning king celebrated
• Inspect the bot's game-state, policy, value, and search data
• Resume an unfinished game automatically
• Hear subtle move, capture, and finish sounds
• Feel lightweight haptic feedback
• Play entirely offline
No ads. No analytics. No tracking. Just chess, two variants, and two bots with very different training.
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