CON (Dungeons & Dragons 5th Edition)
Definition
Constitution has no skills attached to it and it is still the second most valuable ability in the game for nearly every character. Its modifier is added to your hit points at every single level, so a +2 is worth twenty extra hit points by level ten, and that arithmetic never stops compounding. It is also the concentration ability. Losing concentration drops the spell you spent an action and a slot casting, and the save to keep it is a Constitution save with a DC of 10 or half the damage taken, whichever is higher. A caster with a poor Constitution is a caster whose best spells keep falling off after the first hit lands.
How it works
Tips
Frequently asked questions
How much Constitution should a spellcaster have?
At least 14 if you cast concentration spells. The concentration save is a Constitution save at DC 10 or half the damage taken, whichever is higher, and a +2 turns a large share of failures into successes over a campaign.
Do I regain hit points if my Constitution goes up later?
Yes. When the modifier increases, the gain applies to every level you already have, so raising Constitution from 13 to 14 at level 8 adds 8 hit points at once, not just 1 going forward.
Why does Constitution have no skills?
Endurance situations are handled as Constitution saving throws instead of checks, so holding your breath, resisting poison, or marching through the night is a save. That is also why Constitution save proficiency is worth more than it looks.