If a PC becomes stunned on their turn, do they lose the rest of their actions without losing any stunned value?

Question

Page 622 of the Core Rulebook defines the Stunned condition:

You've become senseless. You can't act while stunned. Stunned usually includes a value, possibly over multiple turns, from being stunned. Each time you regain actions (such as at the start of your turn), reduce the number you regain by your stunned value, then reduce your stunned value by the number of actions you lost. ...

I've created a creature that can stun a PC as a result of the PC attacking it with a melee weapon. This means that the PC could be stunned mid-turn.

Now, rules as written, the above paragraph reads like this:

1. You can't act when stunned.
2. Stunned value "ticks down" each time you regain actions.
3. Therefore, if you are stunned during your turn, "you can't act," so you simply lose your remaining actions. Then, at the start of your turn when you regain actions, Stunned ticks down and you may be able to act again on that turn if Stunned reduced to zero.

So, if a PC takes their first action and become Stunned 1, they will actually lose a total of three actions: the remaining two actions on their current turn, then one action when they regain actions next turn.

Is this the correct interpretation? Or should Stunned start ticking down immediately, so that in the above example, the PC would lose their second action on that turn, go down to Stunned 0, and then be able to take their third action?

Answer 1

The character would not lose any actions on its turn. According to the "Gaining and Losing Actions" sidebar (p 622 in the Core Rulebook):

Quickened, slowed, and stunned [...] alter how many actions you regain at the start of your turn; thus, gaining the condition in the middle of your turn doesn't adjust your number of actions on that turn.

The definition of the Stunned condition (also on p 622) reiterates this:

You’ve become senseless. You can’t act while stunned. Stunned usually includes a value, which indicates how many total actions you lose, possibly over multiple turns, from being stunned. Each time you regain actions (such as at the start of your turn), reduce the number you regain by your stunned value, then reduce your stunned value by the number of actions you lost. For example, if you were stunned 4, you would lose all 3 of your actions on your turn, reducing you to stunned 1; on your next turn, you would lose 1 more action, and then be able to use your remaining 2 actions normally. Stunned might also have a duration instead of a value, such as “stunned for 1 minute.” In this case, you lose all your actions for the listed duration.

There are two parts to this definition: the flavor text, which I put in italics in the quoted paragraph, and the mechanical effect, in bold. According to the mechanical effect, you do not lose actions you had already gained; rather, you gain fewer actions the next time you would gain any actions.

Since you don't gain actions at all mid-turn (you already have them), you cannot gain fewer actions mid-turn.

It could also be argued that

You can't act while stunned

is part of the mechanical effect rather than the flavor text (or is both). However, the sidebar text makes clear that the intent is for the condition to kick in only when a character regains actions. Given the flavor text, you could describe using any remaining actions that turn as the character acting via momentum or blind reflex.

Therefore, even if a creature applies Stunned to a PC mid-turn, that PC would be able to use any remaining actions they already have in that turn. Stunned only kicks in at the beginning of the PC's next turn.

Answer 2

Actually it's weirder than that.

1. "You can't act" so the PC does indeed lose all remaining actions. Let us say they lose 2 actions as a result of this.
2. The PC's next turn starts. They "reduce the number [they] regain by [their] stunned value". This is 3.
3. They then "reduce [their] stunned value by the number of actions you lost." This is not 3. Since being stunned, they have actually lost five actions due to the stun and before this bookkeeping phase.

Stunned X no longer means Lose X actions

RAW, the math works out very weirdly. Weirdly enough it's probably good to add a houserule alongside this new ability.

Suppose the character gains Stunned 3. They lose 5 actions, because of the specific timing of the accounting. Then they are no longer stunned. They have lost two more actions than the value of the stun. This actually contradicts the example given (which says if you gain Stunned 4 then you lose 4 actions and can then act again).

Now let us consider instead the character gains Stunned 10 this way. No such extra action loss happens. The first round bookkeeping happens, their turn ends. They now have Stunned 5, having lost 5 actions. Everything now proceeds as if they'd been stunned in the customary way, during another creature's turn. Net effect, Stunned 10 costs the creature 10 actions.

So the consequence is that low values of Stunned gain a very significant buff. Stunned 1 would cost all remaining actions this turn, plus one on the next, for a total of 3. Stun2 would cost 4, Stun3 would cost 5, then Stun4 also costs 5 (2+3 then Stunned is decremented by five*).

Don't do that

This is bad for a few reasons.

1. It's a significant buff to the stunned condition. It effectively puts a minimum floor on it.

2. It takes something simple to understand & easy to apply, and makes it complex with counterintuitive implications.

3. It even contradicts part of the RAW text:

Stunned usually includes a value, which indicates how many total actions you lose, possibly over multiple turns, from being stunned.

TL;DR

Just go with "When stunned X, the character loses their next X actions. Whenever it loses an action to being stunned, decrease X by one. When the value is less than one, the character is no longer stunned and may take any remaining actions it may have available."

Footnote

* Technically, you would have lost 5 actions, you have Stunned 4, so your new stunned value is Stunned -1. Hilariously, the rules don't say what happens if you're "stunned" for a negative value. I bring this up because it's silly to demonstrate that RAW doesn't even actually say Stunned ends upon being reduced < 1. In other words, blindly applying RAW is probably a bad idea here.

Answer 3

Sources Say Yes... unless you think that's too strong.

Broadly speaking, it seems pretty clear that the idea of Stun is that Stun X is going to cost the character X actions. Having a Stun 1 on their turn cost the character as many as 3 actions is a significant increase to the power of the effect... and that actually has some meaning here, beyond vague handwaving claims someone might make about RAI

Core Rulebook, Page 444 says

Sometimes a rule could be interpreted multiple ways. If one version is too good to be true, it probably is. If a rule seems to have wording with problematic repercussions or doesn’t work as intended, work with your group to find a good solution, rather than just playing with the rule as printed.

At the same time, we know what the actual intended rules are, as they're laid out pretty clearly in the sidebar on Gaining and Losing Actions, also in the core rulebook (page 622, I think)

Quickened, slowed, and stunned are the primary ways you can gain or lose actions on a turn. The rules for how this works appear on page 462. In brief, these conditions alter how many actions you regain at the start of your turn; thus, gaining the condition in the middle of your turn doesn’t adjust your number of actions on that turn. If you have conflicting conditions that affect your number of actions, you choose which actions you lose. For instance, the action gained from haste lets you only Stride or Strike, so if you need to lose one action because you’re also slowed, you might decide to lose the action from haste, letting you keep your other actions that can be used more flexibly.

Some conditions prevent you from taking a certain subset of actions, typically reactions. Other conditions simply say you can’t act. When you can’t act, you’re unable to take any actions at all. Unlike slowed or stunned, these don’t change the number of actions you regain; they just prevent you from using them. That means if you are somehow cured of paralysis on your turn, you can act immediately.

The rules also indicate that you lose any leftover actions/reactions at the beginning of your next turn.

So the rules as written indicate that if you start your turn, take a swing with one action and get hit by a Stun 1, then your two remaining actions sit there useless (unless you can somehow cure that stun on your turn), and if you still have a reaction it is likewise useless. At the beginning of your next turn, you lose the leftover actions/reaction as normal, and regain a fresh set, with one less action because of the stun. The stun, at that point, goes away.

If you feel that that's not working as intended, however, or that it has problematic repercussions, you are expected to "work with your group to find a good solution". Alternately, as the GM, you could tweak the rule for yourself, either for this creature, or as a general houserule on the effects of Stun during someone's turn.