When is an action final?

[Star|Scream]

When you cast a spell or play a land, at which point is it final? When the card hits the table? When you announce the card? Is there any opportunity to put a card back into your hand if you mistakenly play it?

[kombatkiwi]

When you cast a spell or play a land, at which point is it final? When the card hits the table? When you announce the card? Is there any opportunity to put a card back into your hand if you mistakenly play it?

Before I attempt to answer this question I want to remind you that if you mistakenly play a card in an illegal way (eg trying to doom blade the opponent's black creature) then call a judge who will most likely rewind the situation and give you a warning (minor penalty).

The main thing to remember is that 'playing' a card and then trying to take it back can be interpreted as trying to fish for a reaction from the opponent, either in an actual action (like a counterspell) or getting a read on their physical/emotional/verbal response. In the case of casting a spell it's quite often the case that once the spell has been announced you are already at this point and therefore I would consider allowing a takeback to be unreasonable. In these situations whether the card has hit the table or not or when you announce it or w/e is not important, as there is nothing in the policy documents which mentions the topic of 'takebacks'. The only relevant factor is whether/when your opponent has become aware of your intention to play the card.

Playing a certain land isn't as big of an issue because the opponent doesn't gain priority but it could still elicit a response and as such once the opponent has seen whatever land that you played I wouldn't allow you to take it back.

For situations like accidentally casting spells into Chalice of the Void it should already be fairly obvious that takebacks are not allowed.

Corner cases arise in which this philosophy cannot be so clearly applied, for example, a player plays scapeshift and searches for his certain 7 lands, putting one land at a time onto the table, and when he reaches the correct number of lands he doesn't have the correct combination of mountains and Valakuts to kill the opponent. The player argues that he was simply dealing out a variety of lands that he could be searching for and that it isn't his final selection.
Such situations are essentially up to the judge's discretion. Again, as far as I know there is nothing in the policy documents pertaining to this issue.

[Arsenal]

Until you present your deck to your opponent, you are considered "searching", even if you pull out a Tundra with Flooded Strand, then take it back and instead pull out an Island instead.

[Star|Scream]

More specifically, if you Announce that you are going to play a tarmogoyf, but you put a dark confidant onto the table, (presumably by accident) you would have to call a judge?

[PirateKing]

A similar question:

What is the limit on a player quietly manipulating their game pieces while in thought?

Examples:

I cast a Samite Archer and ask if it resolves. My opponent quietly thinks, taps :u::u:, quietly thinks some more, untaps :u::u:, and says "Yes it resolves"

At the end of my turn, my opponent taps :1: and activates Sensei's Divining Top. After resolving that ability, they tap the Top, look at their hand, then untap Top and say "Okay my turn"

On their turn, they tap their Thunderscape Master and tap :b::b:, then quietly thinks, then untap :b::b: and tap :g::g: and announce that they are activating it's second ability.

In the declare attacker's step, my opponent taps their Lesser Gargadon, a Ceremonial Guard and Squire. Again after thinking quietly, they untap their Squire and say "These are my attackers"

Disregarding the bizarre deck my opponent is playing, are there any cases where I could call out their choices as had been made, and unable to take back? Or without a verbal announcement of "Tap my Drifting Meadow for white mana" is there no definitive guarantee that a play is genuine?

[cdr]

In general, an action is final after some indication has been made that it's final, or if some information has been gained from pausing after beginning the action.

It's not legal to begin actions in an attempt to gain information - like to see what your opponent's reaction is - and then attempt to not complete them. Looking at your opponent is almost always going to be taken as an indication that your attack/spell/whatever is final.

There is no indication of finality nor information gained in PirateKing's examples.


More specifically, if you Announce that you are going to play a tarmogoyf, but you put a dark confidant onto the table, (presumably by accident) you would have to call a judge?

Assuming you did in fact put the wrong card on the table, which can happen sometimes, yes, a judge should let you play the card you announced.