[larsdangly]

Melee/TFT works as a combat engine because it has simple but specific rules governing movement and actions, which enables players to make meaningful tactical choices, sort of like a game of chess. This only works if both sides understand, accept and follow the rules. A central rule is that your action can be anything that is consistent with your 'option', which is effectively controlled by what you did during the movement phase. You are never committed to the choice of which of those possible actions you must do, until the very moment when you perform it. Think of it as sort of like the way you can move chess pieces around the board however you want until the moment you set one down in a new place and remove your hand - then and only then you are irreversibly committed.