No more than twelve armies in one territory

A territory may never hold more than twelve armies, however they arrive — placing reinforcements, fortifying, or advancing after a conquest. Anything that would push it past twelve stays where it is. Where the rules REQUIRE a placement the cap would forbid — every territory you hold is already at twelve, or a traded-in card names a territory sitting at eleven or twelve — the rules win and the cap yields for those armies only. Without a ceiling the late game collapses into two enormous stacks glaring at each other across one border and nobody can afford to move first; a cap pushes those armies out into territory that has to be held rather than hoarded.