Revivify

Revivify gives you one minute and one diamond to undo a death

At the table. Revivify is a 3rd-level action: touch a creature that died within the last minute and it comes back with 1 Hit Point. It consumes a diamond worth 300+ GP. It can't undo death from old age, and it doesn't regrow missing body parts. There are no dice on this page because there's nothing to roll: it just works, if you're in time and you've got the stone.

What changed from 2014. Who can cast it. In SRD 5.1 Revivify is on the Cleric and Paladin lists. In SRD 5.2.1 it's on the Cleric, Druid, Paladin and Ranger lists, so a party without a cleric has more ways to carry it. The component went from "diamonds worth 300 gp" to one diamond worth 300+ GP.

The clock. One minute is 10 rounds. That sounds like plenty until the fight is still going. The caster needs to reach the body, and the body needs to not be in a dragon's mouth, and then the revived friend stands up on 1 HP in the middle of it.

The choice that matters is buying the diamond before you need it. Most parties who lose someone to a bad round own the spell and not the stone. Put one in the cleric's pack at the first town that sells them, and write it on the sheet.

The common mistake is reviving someone into the same danger that killed them. On 1 HP, one more hit sends them straight back down. Heal them with the next action, or drag them out first; the clock gives you room for one.

The human angle. Kahneman and Tversky's prospect theory found losses loom larger than the equal gains: losing 300 gold hurts more than finding 300 feels good. That's why players balk at spending the diamond on a "just in case", right up until the morning they need it. A diamond is forever. The fighter, less so. For more on what the table does with loss and recovery, see Why D&D Heals.

Source: Kahneman, D., & Tversky, A. (1979). Prospect theory: An analysis of decision under risk. Econometrica, 47(2), 263–291. doi:10.2307/1914185