Aid

Spell FAQs

Below are commonly asked questions about this spell. Some of the information is pulled official D&D sources (such as books and the twitter feeds of D&D officials), but other information is derived from forums and online discussions. As always, it is up to the DM to decide how they wish to spell questions. If you have a FAQ about this spell that you feel other DM's may wish to know, please send us the message!

Will Aid revive/heal fallen characters?

Yes, if the character has not failed 3 deaths saves yet.

If a character has dropped to 0 hit points (or below), they fall unconscious, and must begin making death saves. As long as the character has not failed 3 death saves since they have fallen, any healing they receive will bring them back to consciousness (in the prone position, with their death saves set back to 0). If they have failed 3 death saves, only powerful healing spells (like Revivify, Raise Dead, Reincarnate, Resurrection, True Resurrection, and Wish) may bring back the dead.

What happens when the duration of the Aid spell ends?

The spell states:

Your spell bolsters your allies with toughness and resolve.

However, this buff is only temporary as the spell specifically mentions the duration:

Each target's hit point maximum and current hit points increase by 5 for the duration.

Therefore, when the duration ends, the player loses both the current hit points they gained, and the max hp they gained. So, after 8 hours, an "aided" character with 4 hp would fall to the ground unconscious and have to start making death saves.

What happens with you cast Aid on a character that already is under the effects of Aid?

You can cast Aid as many times as you want, but their effects do not stack. Only if Aid is cast at a higher level on that character, do they receive the higher bonus.

As stated in the PHB p.206:

The effects of the same spell cast multiple times don't combine, however. Instead, the most potent effect — such as the highest bonus — from those castings applies while their durations overlap, or the most recent effect applies if the castings are equally potent and their durations overlap.

There is another, more general rule in the DMG (p. 252) that cover simultaneous effects called Combining Game Effects

Different game features can affect a target at the same time. But when two or more game features have the same name, only the effects of one of them-the most potent one-apply while the durations of the effects overlap. For example, if a target is ignited by a fire elemental's Fire Form trait, the ongoing fire damage doesn't increase if the burning target is subjected to that trait again. Game features include spells, class features, feats, racial traits, monster abilities, and magic items. See the related rule in the "Combining Magical Effects" section of chapter 10 in the Player's Handbook.

And there is yet another version in Xanathar's Guide to Everything (p.4)

Different game effects can affect a target at the same time. For example, two different benefits can give you a bonus to your Armor Class. But when two or more effects have the same proper name, only one of them (the most powerful one if their benefits aren't identical) applies while the durations of the effects overlap. For example, if bless is cast on you when you're still under the effect of an earlier bless, you gain the benefit of only one casting. Similarly, if you're in the radius of more than one Aura of Protection, you benefit only from the one that grants the highest bonus.

So, if Aid is cast a 2nd time (cast at the same level on a character already under the effects of Aid), the character would not gain the benefits from the second casting (since there is no "higher" bonus). However, casting Aid a second time at a higher level, will replace the initial casting.

Can a caster dismiss Aid on it's targets?

No, but casting Dispel Magic will end the effect of Aid. In addition, according to the Sage Advice Compendium (an official FAQ document for Dungeons and Dragons, fifth Edition) [you can check out version 2.3 here for free].

You can't normally dismiss a spell that you cast unless (a) its description says you can or (b) it requires concentration and you decide to end your concentration on it. Otherwise, a spell's magic is unleashed on the environment, and if you want to end it, you need to cast dispel magic on it.