The chesslocke is based on the classic board game of Chess, and forces the player to use strategy much more than in a normal Nuzlocke, mirroring the amount of strategy needed to play chess.
Beside the two classic rules, there is a catch-limiting rule that only allows a max of 15 Pokemon to be caught (giving a total of 16 Pokemon including the starter), as well as a series of rules determining roles for each catch.
Throughout the entire run, you may only have one King, one Queen, two Bishops, two Knights, two Rooks, and eight Pawns. This means you may only catch sixteen Pokemon in the entire run, so skip the first encounters you really don't want (that doesn't mean second chance on the route). You may only have one of each piece on your team at any time.
Each Pokemon you get must be given a role before being able to battle (not the instant they are caught):
- King -Your starter must be the King. The King must always be in your party.
- If the King dies, it's game over.
- Queen -Only female Pokemon may be the Queen.
- The Queen must be in the same egg group as the King
- Bishop -May only have two damaging moves at any time.
- Knight -May not use moves which have a base power greater than 60 (Before STAB).
- Rook -May not use damaging moves that also inflict stats effects on the enemy. They may use non-damaging moves, however. (For example: A Rook can have Tackle because the effect doesn't penalize the enemy, and it can have Spore, because it doesn't do damage, but not Ember, because it does damage and has a negative effect on the enemy.)
- Pawn -May only be a Pokemon that has stats of maximum 450 altogether, must be first form and cannot be evolved. It may only have one attacking move, and that must be lower than 80 base power (Before STAB).
If a pawn wins a major battle alone (rival, gym leader, villainous team admin), it may upgrade to a rook, knight, bishop or queen. (It can only upgrade to a queen if the queen is dead.)