エンチャント
エンジン始動!(あなたが速度を持たないなら、1から始まる。速度はあなたの各ターンに1回、対戦相手がライフを失ったとき、1上がる。最高速度は4である。)
このエンチャントが戦場に出たとき、あなたはカード1枚を捨ててもよい。そうしたなら、カード2枚を引く。
最高速度 — このエンチャントを生け贄に捧げる:ターン終了時まで、あなたがコントロールしていてクリーチャーや機体であるすべては速攻を得る。
Your speed doesn’t change until a spell or ability says so, such as the inherent triggered ability that cares about opponents losing life during your turn. Notably, losing control of permanents with start your engines! doesn’t affect your speed.
A player “has max speed” if their speed is 4.
If an effect needs to know what a player’s speed is and that player doesn’t have a speed, their speed is considered 0.
Start your engines! isn’t a triggered ability. Increasing your speed to 1 is something that happens as a state-based action as soon as you control a permanent with the ability. Notably, this includes gaining control of a permanent with the ability that another player controls.
Each player tracks their speed (or lack thereof) separately. Increasing your speed has no effect on whether another player has speed.
“Max speed — [ability]” means “As long as you have max speed, this object has [ability].” If the granted ability functions in a zone other than the battlefield, the max speed ability does too.