What happens if you lose haste during your turn?

[holywhippet]

What happens in this scenario: A wizard casts haste on themselves in round 1. In round 2 they move which provokes an AoO. They take a hit and fail their concentration save. Do they a) miss the rest of their turn or b) miss the rest of their turn and can't act until the end of their next turn?

Also, if a boss type monster with legendary actions loses a haste spell on them, do they lose access to their legendary actions until after their next turn?

[mephnick]

As it's written I'd say it's A). It gives no allowance to finish your current turn as normal.

The monster would lose Legendary Actions until after it's next turn, but I'd say Lair Actions would function as normal.

[holywhippet]

Thanks, but now for a part 2 to the question. What happens if a character is concentrating on haste on themselves and then tries to cast another concentration spell? Does casting the other spell fail because as soon as they drop concentration on haste they can't act. Or does the other spell succeed but it is an automatic end of turn?

[BloodOgre]

Thanks, but now for a part 2 to the question. What happens if a character is concentrating on haste on themselves and then tries to cast another concentration spell? Does casting the other spell fail because as soon as they drop concentration on haste they can't act. Or does the other spell succeed but it is an automatic end of turn?

If you are hasted, you can only cast a spell as your first action. Your second action cannot be casting a spell (bummer for casters). So, casting the other spell succeeds and the caster is no longer hasted and no longer gets any further benefits (additional action, +2AC, etc). further, the caster cannot take any actions until after it's next turn.

"Choose a willing creature that you can see within range. Until the spell ends, the target's speed is doubled, it gains a +2 bonus to AC, it has advantage on Dexterity saving throws, and it gains an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action.

When the spell ends, the target can't move or take actions until after its next turn, as a wave of lethargy sweeps over it."

[holywhippet]

If you are hasted, you can only cast a spell as your first action. Your second action cannot be casting a spell (bummer for casters). So, casting the other spell succeeds and the caster is no longer hasted and no longer gets any further benefits (additional action, +2AC, etc). further, the caster cannot take any actions until after it's next turn.

"Choose a willing creature that you can see within range. Until the spell ends, the target's speed is doubled, it gains a +2 bonus to AC, it has advantage on Dexterity saving throws, and it gains an additional action on each of its turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action.

When the spell ends, the target can't move or take actions until after its next turn, as a wave of lethargy sweeps over it."

Sorry, I think you missed my question. Say a wizard casts haste on themselves in the first round of combat. Then in the second round of combat they cast a different concentration spell - say invisibility. The rules for haste say you can't take actions until the end of your next turn when the spell ends which it will when you break concentration by casting a new concentration spell. So if cast invisibility does that automatically fail because you can no longer take an action?

[MaxWilson]

Sorry, I think you missed my question. Say a wizard casts haste on themselves in the first round of combat. Then in the second round of combat they cast a different concentration spell - say invisibility. The rules for haste say you can't take actions until the end of your next turn when the spell ends which it will when you break concentration by casting a new concentration spell. So if cast invisibility does that automatically fail because you can no longer take an action?

That leads to paradox, so I'd say no: you are now invisible and lethargic. You will miss your next action, but you didn't miss your action this turn, or you'd still be Hasted.

I recognize that this is a DM call, but as DM that would be my call.

[Platypusbill]

Sorry, I think you missed my question. Say a wizard casts haste on themselves in the first round of combat. Then in the second round of combat they cast a different concentration spell - say invisibility. The rules for haste say you can't take actions until the end of your next turn when the spell ends which it will when you break concentration by casting a new concentration spell. So if cast invisibility does that automatically fail because you can no longer take an action?

Rules:

The following factors can break concentration:

-Casting another spell that requires concentration. You lose concentration on a spell if you cast another spell that requires concentration. You can’t concentrate on two spells at once.

The text doesn't specify if your spell is considered cast as soon as you start doing it or when you finish the casting and the spell takes effect, so there doesn't seem to a conclusive answer. But I'd rule that Haste ends when you finish casting Invisibility, and thus you gain its benefits (albeit at a heavy cost).

[RSP]

JC has tweeted that as soon as you start casting a Con spell, and other Conc spells end. If playing by that, the caster would lose concentration on Haste and their Action casting the new spell as soon as they start casting the new spell.

[Isaire]

"When the spell ends, the target can't move or take actions until after its next turn, as a wave of lethargy sweeps over it."

I don't tend to follow JC's tweets, so I would say that you can cast invisibility. However, in common english, you cast invisibility on this turn, so after your next turn would mean that turn 3 is spent unable to act.