Starting and Stopping Full-Round Actions

[Morof Stonehands]

A question came up in my game the other day that’s been bugging me.

If a Havoc Mage uses its Battlecast ability (which is a full-round action) to attack and cast a spell that targets the creature he is attacking, in what order do they happen? I would assume the most beneficial order.

Now, if they decide to attack first, and kill the creature, can they not cast the spell, and cancel the rest of that full-round action? It would make sense that they could, but since they’ve declared they’re using that ability, does the whole ability happen anyways?

On the other side, if they use a regular attack, and don’t kill the creature, is it a valid move to then turn their action into a full-round action to Battlecast, similar to declaring a full-attack?

[One Step Two]

You need to declare the use of Battlecast as a full round action, however when reading the ability, it doesn't distinguish that the target of the attack and the spell must be the same.

So, you could prepare a ranged touch spell, such as Scorching Ray, and swing your sword. If the swordblow kills your melee target you can then cast the spell picking any other valid target that fits the spell descriptor.

If you are casting a touch range spell, and you only have 1 valid target then you hold the charge in your hand if you kill that target first.

If you declare to use Battlecast, that is your action for the turn, regardless of targets remaining in range, you cannot choose to move. However, you can make use of the Start/Complete Full-Round Action (https://www.d20srd.org/srd/combat/actionsInCombat.htm#startCompleteFullRoundAction) rules. You move, spend a standard action to prepare to use Battlecast. Then the following turn, complete the use of Battlecast as a standard action, and then move again.

[Fizban]

It says attack and cast a spell, so my first thought is you attack and cast a spell (as in, the sentence already has them in an order). But I could also see it being read as: by not specifying the order of your actions you are left to choose the order in which they occur, since you normally choose the order you take your actions in, and in absence of anything else this does seem like the more appropriate choice. And if you're picking your actions as they go, you aren't picking the spell until it's spell time either (and the lack of being required to pre-specify also implies you're choosing what's going on).

It also says may, so if the results of the attack make you change your mind about the spell, I see no reason you could not simply abort and leave it at the single attack. Though because the ability does specify a full round action you've already used that, so no refund on move action or transitioning into full attack.

[Morof Stonehands]

Thank you both! That clears a lot of things up.