Inferno Titan

Creature — Giant

: This creature gets +1/+0 until end of turn.

Whenever this creature enters or attacks, it deals 3 damage divided as you choose among one, two, or three targets.

You divide the damage as you put Inferno Titan's triggered ability on the stack, not as it resolves. Each target must be assigned at least 1 damage. (In other words, as you put the ability on the stack, you choose whether to have it deal 3 damage to a single target, 2 damage to one target and 1 damage to another target, or 1 damage to each of three targets.)