Now that reversing decision is a few months old, its limits have been tested quite some. Today, I’d like to address one specific topic that comes back regularly: Can a player ask to reverse a decision so as to be able to claim a Trigger they missed?
Short story: That is (sometimes) possible.
Longer story: It depends as to whether information has been gained or not.
Bottom line: If you’re not sure, then do not allow the decision to reversed.
Howard plays a land, pauses, then casts a Gravecrawler. Before anything else happens, Howard realizes they have a Bloodghast in their graveyard and would like to take back the Gravecrawler.
Even if Howard’s goal is certainly to bring back Bloodghast, Howard’s request technically boils down to: “Can I change my mind and not cast this Gravecrawler?”
At this point, MTR 4.8 should be examined: It does not seem that Howard gained any extra information, therefore the judge can authorize Howard to not cast Gravecrawler.
Once Gravecrawler’s casting has been reversed, the game state still potentially allows the triggered ability to be on the stack: There is nothing anymore that would prove that the trigger has been missed. Therefore it can still be claimed.
MTR4.8 – […] If that player has not gained any information since taking the action and they wish to make a different decision, a judge may allow that player to change their mind. Judges must carefully consider whether the player has gained information since making the play that might have affected the decision; in particular, players may not try to use opponent reactions (or lack thereof) to see if they should modify actions they committed to. If the judge cannot be sure no information was gained, they should not allow the decision to be changed.
Overall, the fact a trigger was missed is a red herring.
When you apply reversing decisions, you make a conscious decision to bring back the game state to what it was prior to the play that was reversed. Other actions are collateral consequences and should not be considered, unless they led to gaining information.
To a similar extent, if a GRV has been committed and the game state is backed up to the point of the mistake, the player may claim a trigger they had previously forgotten. This is incredibly close.
Finally, the Missed Trigger policy has never intended to create a “Gotcha” environment: Its primary goal was to not force a player to remind their opponent of a trigger that would make that player die.
The interaction between Reversing Decisions and Missed Trigger does not harm this goal and reduces even more the collateral “Gotcha” aspect, which has always existed as part of the Missed Trigger policy.