Does your character know when a buff spell ends?

[Goladar]

What it says on the tin. Specifically in regards to Anticipate Teleportation.

[Elkad]

Your own buffs?

I can't think of a ruling, but I'd assume yes. The "load meter" on your source of magical energy drops.

The DM saying "you have to ask" in the case of it dropping unexpectedly would be fine.

[Goladar]

The DM saying "you have to ask" in the case of it dropping unexpectedly would be fine.

Could you expound on that?

[Geddy2112]

If the spell has a fixed duration, you would be able to estimate when it expires. Also, any spell you cast you know if it has been dispelled/resisted/fails, so you should know when it ends as well.

If you did not cast the spell, it depends. Some spells are pretty obvious and you would feel/see/sense them going away, or indirectly realize it from losing their benefit(you know the fly spell is wearing off since you are floating down to the ground). If somebody cast anticipate teleportation on you, I am not sure you would know it ended unless you were also a caster and could detect the magic around you/identify the spell.

[Goladar]

Also, any spell you cast you know if it has been dispelled/resisted/fails, so you should know when it ends as well.


Is there a rule quote about this somewhere?

[Psyren]

Fixed duration yes, variable duration no (unless you have an external means of detection up, like arcane sight, to "keep an eye on it.")

Relevant rule:


Timed Durations

Many durations are measured in rounds, minutes, hours, or some other increment. When the time is up, the magic goes away and the spell ends. If a spell’s duration is variable the duration is rolled secretly (the caster doesn’t know how long the spell will last).

The inverse to the bolded rule of course means that if the duration is NOT variable, the caster knows what it is. This makes sense in-universe too - if a caster knows a spell, he knows what's on its "Duration" line, and of course they know their own caster level, so extrapolating a fixed duration spell is easy. This is true even for other fixed durations - Permanent and Instantaneous are moot as they don't need to be tracked, and Concentration requires action from the caster to maintain.

[tomandtish]

Fixed duration yes, variable duration no (unless you have an external means of detection up, like arcane sight, to "keep an eye on it.")

Relevant rule:



The inverse to the bolded rule of course means that if the duration is NOT variable, the caster knows what it is. This makes sense in-universe too - if a caster knows a spell, he knows what's on its "Duration" line, and of course they know their own caster level, so extrapolating a fixed duration spell is easy. This is true even for other fixed durations - Permanent and Instantaneous are moot as they don't need to be tracked, and Concentration requires action from the caster to maintain.

However, knowing that the spell will last three hours (for example) does not automatically guarantee that you know exactly when three hours have passed.

The majority of people are actually bad at estimating how much time has passed, and it tends to get worse the longer has gone by. I had a GM who played with a default of +/- 10% when estimating time without assistance. This can be improved by 1% times your wisdom modifier (so actually got worse with a negative modifer).

So with no modifier or assistance (hour glass, magic time keeping, etc.), you might peg an hour anywhere between 54 - 66 minutes. Close enough for jazz if the spell isn't critical. But you could be off by over 2 hours when estimating a 24 hour period.

Of course, you could get modifiers for other things (dawn, dusk, etc.).

[Psyren]

However, knowing that the spell will last three hours (for example) does not automatically guarantee that you know exactly when three hours have passed.

It wouldn't for us, but honestly, I would just rule this kind of mental note is part of a caster's training unless they're specifically in a location that messes with their perception of time (or time itself) in some way.

When Vaarsuvius tells Roy a spell he cast is about to run out, I don't see him checking his watch or peeking at an hourglass or anything. He just knows, because he knows how the spell works and is counting in his head.

[Goladar]

Fixed duration yes, variable duration no (unless you have an external means of detection up, like arcane sight, to "keep an eye on it.")

Relevant rule:



The inverse to the bolded rule of course means that if the duration is NOT variable, the caster knows what it is. This makes sense in-universe too - if a caster knows a spell, he knows what's on its "Duration" line, and of course they know their own caster level, so extrapolating a fixed duration spell is easy. This is true even for other fixed durations - Permanent and Instantaneous are moot as they don't need to be tracked, and Concentration requires action from the caster to maintain.

What if the spell was ended prematurely? For example, time traveling can end your spells.

[Psyren]

What if the spell was ended prematurely? For example, time traveling can end your spells.

Like I said above, if something messes with time or with the character's perception of time in some way, you'll have to adjudicate that individually. I'm only describing what happens in the normal case.

[Elkad]

Could you expound on that?

If something was to suppress/cancel your spell (especially if you had a jillion buffs running and it only squashed one), you might not notice.

But if you specifically asked "are all my buffs OK?", you'd still know, as you did a little mental inventory (or "examined the magical weave" or whatever) and realized one was missing.

I'd go with the first option (you automatically know), barring some special circumstance. Like if there was some way to have a running buff pickpocketed.
You don't notice you've been robbed automatically, but if you say "I check my belongings" or just try to pay for your lunch, the DM says "Your wallet is gone!"