Nice to meet you!

The situation is a Player(=NAP) is controlled by another player(=AP) by the ability (ex:“Mindslaver”,“Emrakul, the Promised End”…).

In this situation, if players missed a triggered ability which is “NAP draw a card” controlled by NAP, whom does Judge give a penalty, and which is penalty Warning or None ?

On the other hand is it “AP draw a card” controlled by NAP ?

I think AP is controller of NAP, is not controller of trigger abilities NAP has.

CR712.3 Only control of the player changes. All objects are controlled by their normal controllers.

So yes, controlling another player does not make you the controller of their permanents or their triggered abilities.

IPG 2.1 (Excerpt) Even if an opponent is involved in the announcement or resolution of the ability, the controller is still responsible for ensuring the opponents make the appropriate choices and take the appropriate actions. Opponents are not required to point out triggered abilities that they do not control, though they may do so if they wish.

In your example, because the triggered ability is controlled by “NAP,” NAP would have committed the infraction, and would receive no penalty.

Thank you Robert !!

I posted this question because I want to check my thinking is colect.
This purpose has been archived.

FYI there's a rules Q&A section on the forum which is better suited. Competitive REL is aimed more at discussion topics ;)

Philosophy-wise, does it really make sense for NAP to still be responsible for his own triggers when being controlled by AP? Often when a player is being controlled, they let the opponent take all the physical actions required, and pay less attention to the game state as a consequence. This means that AP would be able to intentionally “miss” triggers that, in practice, he is in control of. Would it be reasonable to make players responsible for any triggers controlled by a player they control?

You can't assume that AP (here) knows exactly how how the cards of NAP work and how things would trigger exactly etc. And paying less attention is definitly not something that i would consider as “normal” when being mindlsaved, on the contrary (and intentionally missing a trigger in order to gain an advantage, knowing that's it's illegal is a good way to be DQ).

When players ask me about Mindslaver type effects and trigger responsibilities I point out that controlling another player's turn is basically the controlling player A makes all the decisions for that turn, but it's still the player B's turn so Player B is responsible for remembering the triggers just that Player A makes any decisions for the triggers.

712.3 Only control of the player changes. All objects are controlled by their normal controllers. A player who’s being controlled during his or her turn is still the active player.

712.5 While controlling another player, a player makes all choices and decisions the controlled player is allowed to make or is told to make by the rules or by any objects. This includes choices and decisions about what to play, and choices and decisions called for by spells and abilities.

I don't believe that the Missed Trigger philosophy should change because players decide to ignore their own turn because it's being controlled by their opponent.

This has come up before.
And something very similar, as well.

And just as I said in each of those - well, I'll shorten it, this time: Mark Brown is correct.

d:^D

Question has been asked and answered but I want to point out one more key element of policy. The philosophy of Missed Triggers says as follows: “Players may not cause triggered abilities controlled by an opponent to be missed by taking game actions or otherwise prematurely advancing the game.” The active player deserves a reasonable amount of time to remember triggers, and we should remind players who try to rush past opponents' triggers that we discourage such behavior.