MTR 4.8 – Reversing decisions


It sometimes happens that a player takes the wrong card from their hand and puts it on the table.

While it may be easy to be sure this was not the correct card – No, that Arboretum Elemental was (most likely) not what was intended to be played on turn 2 out of those two lands -, it can be a lot trickier to determine what should happen when a player plays a Mountain from their hand, before saying they wanted to actually play a Forest when they have both Wild Nacatl and Goblin Guide in hand.

Since the first play is not legal, it needs to be reversed. But what about the second, for which no infraction has occurred?



Creating a rule

Until now, there were no rules explicitly allowing players to revert a decision they made, unless that decision was illegal (Comprehensive Rules – 721. Handling Illegal Actions ; MIPG – at many places!)

However, even if the spell could be legally cast, if it was clear that a player took the wrong card in their hand, for instance because they announced another card name as they cast it, they tapped a number of lands that coincidentally matched the cost of another spell in their hand or the spell they cast on their opponent’s creature was a pump spell mid-combat rather than a removal, judges were usually allowing the player to cast the spell they wanted to cast. While this felt like falling under common sense, this nevertheless led to a wide range of interpretation amongst the community as to whether reversing this decision should be allowed.

Increasing consistency and giving guidance on how to operate in such cases were the decisive factors in creating this rule.



Allowing players to change their minds

From there, we needed to wonder what the difference was between a player taking the wrong card in their hand or a player realizing immediately after they made a play they in the end wanted to do something else.

I’ve mostly talked about the player’s intent so far, since it was the basis of the reasoning, but the opponent needed to be protected as well. Since we expect clear communication, it should not be up to the opponent to ensure whether a play was final or not.

It is reasonable for the opponent to assume that once a play has been done, it is locked in. While there is no rule explicitly stating this, if you do not operate under that assumption, it becomes tedious for the opponent to know when they can respond.

Basically, we wanted to create a rule that would operate in the interest of making games play as they should, a fair rule that no player could take advantage of.



The decisive criteria: Information gained

We quickly realized that without cautious crafting, allowing players to reverse a decision they made may grant them an opportunity to take advantage by trying to generate a reaction, then changing their mind, so we’ve been very cautious to prevent this from happening:


First, we make it clear that this rule does not remove responsibility for clear communication:

Players are expected to consider their options before taking an action and players are not usually allowed to take back an action that has been communicated to their opponent, either verbally or physically.


Then, we define the boundaries of this rule:

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

Note the usage of may: Players have not become entitled to reversing their decisions.


Before giving some guidance:

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.

It’s not because nothing has happened that allowing a player to reverse a decision is safe. A non-reaction can be just as telling as a reaction. This is especially true when the opponent could cast instants in response to a spell. If they do nothing, they may have revealed information about the content of their hand.


And finally, the most important piece of this rule is certainly this one:

If the judge cannot be sure no information was gained, they should not allow the decision to be changed.

The default option is always to have the player adhere to the first choice they made.
Similar to our GRV backup policy, the default option is to leave the situation as it is. If the judge believes that everything is straightforward, and the player could not take advantage of the confusion, then they may allow them to revert their decision.


This is what the examples describe:

1. A player plays an Island and, before anything else happens, says “Sorry, I meant to play a Swamp.”
2. A player says “No blocks” immediately followed by “Wait, no, I block with this creature.”
3. A player says “Go. Wait, land, go.”



In short, this new policy aims at facilitating and promoting smooth play, while keeping adequate communication.

Once again, reversing a decision taken is not something players are now entitled to do – they remain responsible for their choices and the default action remains to “leave as it is” -, but if, within the established boundaries (no window to take advantage by gaining information in the process), the judge determines that they can allow the player to reverse their action, their decision is now cleanly supported by the rules.


Kevin Desprez