DeathtouchDeathtouch is a static ability.
A creature with toughness greater than 0 that’s been dealt damage by a source with deathtouch since the last time state-based actions were checked is destroyed as a state-based action. See rule 704.
Any nonzero amount of combat damage assigned to a creature by a source with deathtouch is considered to be lethal damage for the purposes of determining if excess damage is being dealt.
The deathtouch rules function no matter what zone an object with deathtouch deals damage from.
If an object is no longer in the zone it’s expected to be in as an effect causes it to deal damage, its last known information is used to determine whether it had deathtouch.
Multiple instances of deathtouch on the same object are redundant. (CR 702.2)
The first instant or sorcery spell you
castTo cast a spell is to take it from the zone it’s in (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. A player may cast a spell if they have priority. See rule 601, “Casting Spells.”
To cast a card is to cast it as a spell. (CR 701.5) each turn has
casualtyCasualty is a keyword that represents two abilities. The first is a static ability that functions while the spell with casualty is on the stack. The second is a triggered ability that functions while the spell with casualty is on the stack. Casualty N means “As an additional cost to cast this spell, you may sacrifice a creature with power N or greater,” and “When you cast this spell, if a casualty cost was paid for it, copy it. If the spell has any targets, you may choose new targets for the copy.” Paying a spell’s casualty cost follows the rules for paying additional costs in rules 601.2b and 601.2f–h.
If a spell has multiple instances of casualty, each is paid separately and triggers based on the payments made for it, not any other instance of casualty. (CR 702.153) 2. (As you
castTo cast a spell is to take it from the zone it’s in (usually the hand), put it on the stack, and pay its costs, so that it will eventually resolve and have its effect. A player may cast a spell if they have priority. See rule 601, “Casting Spells.”
To cast a card is to cast it as a spell. (CR 701.5) that spell, you may
sacrificeTo sacrifice a permanent, its controller moves it from the battlefield directly to its owner’s graveyard. A player can’t sacrifice something that isn’t a permanent, or something that’s a permanent they don’t control. Sacrificing a permanent doesn’t destroy it, so regeneration or other effects that replace destruction can’t affect this action. (CR 701.21) a creature with power 2 or greater. When you do, copy the spell and you may choose new targets for the copy.)