We are well on our way in a 5e campaign, but everyone getting fully healed after a long rest takes some of the sense of danger out of the game. I am looking for a set of rules that would give meaningful injuries on a critical hit.
For example, an orc rolls a natural 20, then you roll on a second table and end up with a broken arm. Then with that broken arm you can still heal up to max hp, but your arm is broken — no two-handers, no shield...
The 5e Dungeon Master's Guide contains an optional rule on p.272:
Lingering injuries
A creature might sustain a lingering injury under the following circumstances:
- When it takes a critical hit
- When it drops to 0 hit points but isn't killed outright
- When it fails a death saving throw by 5 or more.
When an injury happens, the player has to rule a d20, and there is a table. Some examples are
The generally have some suitable negative mechanical effects attached (no two-handed weapons for a single-handed warrior). Most of the injuries can be healed using magic, but some of the worse ones require a high level spells such as L7 regenerate. This means that removing the injury can be integrated into the story, especially for lower level parties, as they would need some higher level NPC to heal them.
We used the lingering injuries rule on crits and death saves in our last session, and they were great. They make crits memorable, and create fear and despair in players similar to the older editions death and dismemberment table. I can only recommend you to use these rules.
If your DM only wants to use a less severe table, he is of course free to create one himself. Googling for 'death and dismemberment' should find plenty of options in various forms of severity. A table I used for an earlier campaign can be found here.
WOtC has recently released some variant rules. Among these is a "vitality" rule, which temporarily reduces your maximum hit points when you take large amounts of damage (>10 hp), effectively making it take longer to completely heal the damage taken during a fight.
In general, each character has a "Vitality Pool" which begins equal to your Constitution score. The Vitality Pool is reduced when they take large amounts of damage. As your vitality drops, you lose hit points as if your maximum hit points were calculated by Vitality Pool points instead of your Constitution score.
This reduction in hit points can be described in whatever manner you want (broken arm), but doesn't have any other mechanical detriments: it doesn't make it impossible to use your equipment.
Make a Con check, GM sets the dc based on the wound.
On a failed check, roll percentile:
01–40: nothing lingering other than a scar
40–50: broken ribs — one action per turn
51–60: broken limb — roll 1d4 to determine which:
