No Legal Target: Rewind Everything
Judge Level 1Doom Blade against a hexproof Bogle — why the spell doesn't even stay on the stack.
Cards involved
Doom Blade without a target
The only creature your opponent controls is a Slippery Bogle with hexproof. You tap two lands and put Doom Blade on the stack …
601.2To cast a spell is to take it from where it is (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. Casting a spell includes proposal of the spell (rules 601.2a–d) and determination and payment of costs (rules 601.2f–h). To cast a spell, a player follows the steps listed below, in order. A player must be legally allowed to cast the spell to begin this process (see rule 601.3). If a player is unable to comply with the requirements of a step listed below while performing that step, the casting of the spell is illegal; the game returns to the moment before the casting of that spell was proposed (see rule 733, “Handling Illegal Actions”).
What happens?
While choosing targets you realize:
The Bogle has hexproof — you can't target it, and there is no other legal target. What happens?
Pick an answer to continue.
601.2cThe player announces their choice of an appropriate object or player for each target the spell requires. A spell may require some targets only if an alternative or additional cost (such as a kicker cost) or a particular mode was chosen for it; otherwise, the spell is cast as though it did not require those targets. Similarly, a spell may require alternative targets only if an alternative or additional cost was chosen for it. If the spell has a variable number of targets, the player announces how many targets they will choose before they announce those targets. In some cases, the number of targets will be defined by the spell’s text. Once the number of targets the spell has is determined, that number doesn’t change, even if the information used to determine the number of targets does. The same target can’t be chosen multiple times for any one instance of the word “target” on the spell. However, if the spell uses the word “target” in multiple places, the same object or player can be chosen once for each instance of the word “target” (as long as it fits the targeting criteria). If any effects say that an object or player must be chosen as a target, the player chooses targets so that they obey the maximum possible number of such effects without violating any rules or effects that say that an object or player can’t be chosen as a target. The chosen objects and/or players each become a target of that spell. (Any abilities that trigger when those objects and/or players become the target of a spell trigger at this point; they’ll wait to be put on the stack until the spell has finished being cast.)
733.1If a player takes an illegal action or starts to take an action but can’t legally complete it, the entire action is reversed and any payments already made are canceled. No abilities trigger and no effects apply as a result of an undone action. If the action was casting a spell, the spell returns to the zone it came from. Each player may also reverse any legal mana abilities that player activated while making the illegal play, unless mana from those abilities or from any triggered mana abilities they caused to trigger was spent on another mana ability that wasn’t reversed. Players may not reverse actions that moved cards to a library, moved cards from a library to any zone other than the stack, caused a library to be shuffled, or caused cards from a library to be revealed.
Why rewind instead of fizzle?
Fizzling only happens when a legally cast spell loses its target later (see the scenario "Fizzling Is Not Countering"). Here the cast itself was already illegal — hence rewind instead of graveyard.
702.11Hexproof
733.1If a player takes an illegal action or starts to take an action but can’t legally complete it, the entire action is reversed and any payments already made are canceled. No abilities trigger and no effects apply as a result of an undone action. If the action was casting a spell, the spell returns to the zone it came from. Each player may also reverse any legal mana abilities that player activated while making the illegal play, unless mana from those abilities or from any triggered mana abilities they caused to trigger was spent on another mana ability that wasn’t reversed. Players may not reverse actions that moved cards to a library, moved cards from a library to any zone other than the stack, caused a library to be shuffled, or caused cards from a library to be revealed.
Rule of thumb
Targets are chosen before costs are paid (601.2c before 601.2h). So check first whether you can legally target at all — hexproof, protection and "can't be targeted" already block the announcement.
608.2bIf the spell or ability specifies targets, it checks whether the targets are still legal. A target that’s no longer in the zone it was in when it was targeted is illegal. Other changes to the game state may cause a target to no longer be legal; for example, its characteristics may have changed or an effect may have changed the text of the spell. If the source of an ability has left the zone it was in, its last known information is used during this process. If all its targets, for every instance of the word “target,” are now illegal, the spell or ability doesn’t resolve. It’s removed from the stack and, if it’s a spell, put into its owner’s graveyard. Otherwise, the spell or ability will resolve normally. Illegal targets, if any, won’t be affected by parts of a resolving spell’s effect for which they’re illegal. Other parts of the effect for which those targets are not illegal may still affect them. If the spell or ability creates any continuous effects that affect game rules (see rule 613.11), those effects don’t apply to illegal targets. If part of the effect requires information about an illegal target, it fails to determine any such information. Any part of the effect that requires that information won’t happen.
Stack
Doom Blade
Destroy target nonblack creature … wait.
Slippery Bogle
Hexproof — can't be the target of your spells
The stack is empty.
Battlefield
—