Incapacitation ends concentration
Under D&D 2024, Unconscious includes Incapacitated, and that condition breaks concentration. In the ordinary case where a character reaches zero hit points, does not die and falls unconscious, a damage-triggered Constitution save cannot preserve the spell despite that condition.
Resolve the character’s condition before rolling out of habit. The concentration damage rule does not replace unconsciousness rules. We use the 2024 Basic Rules and glossary; consult your DM about any trait or effect changing this scenario.
Four hit points, four damage
In this invented example with no exceptional traits, your character has 4 current HP, is concentrating on a spell and takes 4 resolved damage. Their maximum is not zero, the case causes no instant death, and no rule allows them to remain conscious.
The record changes from 4 to 0 HP. They fall unconscious in this scenario, become incapacitated and lose concentration. A good roll cannot restore the ended effect. Do not confuse the Constitution save with Death Saving Throws either: these are separate procedures to resolve when applicable.
This guide neither calculates the entire turn nor recommends an extra roll. It isolates a check that prevents accidentally retaining concentration while updating HP.
What if you later receive one point of healing?
Suppose a valid effect restores 1 HP. The rules say unconsciousness caused by dropping to zero ends when HP is regained, but this does not recast a spell whose concentration already ended. Keep “I now have 1 HP” separate from “the earlier effect remains active”; the second does not follow from the first.
To create an effect again, check the actual actions, resources and conditions it requires. Do not restore a spell slot or add an active spell merely because the character is conscious again. Other conditions may remain; the glossary notes, for example, that ending Unconscious does not itself remove Prone.
Update the sheet after resolution
DnD Dynamic Sheet documents HP, spells, notes and custom counters. Use your record to retain what ended and what still needs table resolution. The product facts do not establish that the app detects this sequence, rolls saves or automatically removes every effect: the example is a manual check.
It is a paid Windows beta focused on the player’s sheet, with local characters and initial online activation. Review its recordings and scope on the home page. Before continuing this case, check two things: current HP and the concentration effect that has already ended.