Phase D.2 of the rule-variants epic. Inverse objective of
suicide-chess: you win by driving the opponent's piece count to 0.
Kings are not royal, captures are NOT compulsory.
Wiring uses three existing hooks:
- getRoyalPieces → [] per color (no royalty).
- shouldFilterSelfCheck → false (opt out of the filter; kings can
legally wander into attacked squares).
- onCheckGameResult → count live Position facts per color; 0 for
the opponent wins for the mover. Otherwise returns 'ongoing' to
suppress the default checkmate/stalemate polls (which are
ill-defined under empty-royal semantics).
No filterLegalMoves — captures are optional, which is the chief
rule-text difference from suicide-chess.
Incompatible with every other terminal-decider preset
(capture-to-win, last-piece-standing, first-promotion-wins,
suicide-chess, extinction-chess) and with presets that redefine
royalty (knightmate-rules, coregal, dual-king, weak-dual-king).
monster-rules already declares capture-all incompatible on its
side; mirror it here.
Joey Yakimowich-Payne
5d64ae4c37