行侣

万智牌机制

你每盘游戏至多只能选择一个行侣。开始游戏时，所选的行侣并不在你的主牌；而是在你的备牌中。也就是说，它不会计入你所玩赛制的套牌最低张数限制；而在构组赛制中，它是你的十五张备牌之一。在游戏开始前，你向所有牌手展示你所选的行侣。在游戏过程中，你可以支付{3}来将所选行侣置于你手上，但只能在你的行动阶段中堆叠为空的时机下如此作，且每盘仅限一次。

行侣规则

A keyword ability that allows a player to choose one creature card from outside the game as a companion if the restriction of that card’s companion ability is met. Once a player has chosen a companion, that player may pay {3} to put it into their hand once during the game. See rule 702.139, “Companion.”

702.139a： Companion is a keyword ability that functions outside the game. It’s written as “Companion—[Condition].” Before the game begins, you may reveal one card you own from outside the game with a companion ability whose condition is fulfilled by your starting deck. (See rule 103.2b.) Once during the game, any time you have priority and the stack is empty, but only during a main phase of your turn, you may pay {3} and put that card into your hand. This is a special action that doesn’t use the stack (see rule 116.2g). This is a change from previous rules.
702.139b： If a companion ability refers to your starting deck, it refers to your deck after you’ve set aside any sideboard cards. In a Commander game, this is also before you’ve set aside your commander.
702.139c： Once you take the special action and put the card with companion into your hand, it remains in the game until the game ends.
702.139d： Cards can enter Commander games from outside the game via the companion special action.