ThatGuySteve
Explorer
I've seen too many combats with characters bouncing up and down, from 0hp, getting a Healing Word to give a handful back, getting knocked down again. There is no sense of fear to going into combat.
The grittier variant rule in the DMG to slow down healing and regaining hit dice just slows the campaign, it doesn't make combat deadlier.
There are quick fixes, like making death save failures reset only on a short or long rest so that deadlines builds up over the course of the day. However you might get you Healing Word in every round before you need to make a save.
A harsher effect could be gaining a level of exhaustion each time you drop to 0hp. That might be too harsh though and turn into a quick death spiral. You might get a level of exhaustion right at the start of the day and be wrecked for the rest of the adventure, which isn't much fun.
More complex (but that's what we're here for) could be something like tracking Wounds. You start with Wounds equal to your Constitution score. Each time you drop to 0hp, are hit by a critical hit, take damage greater than 50% (or maybe 25%) of your total hit points, you lose a wound. Once you are below 50% your total wounds, get a level of exhaustion that can't be removed. Once below 25% gain a second level of exhaustion.
Once you hit 0 wounds, your dead, no saves. Or once you hit 0 wounds you are dying but can't stabilise, you just keep making death saves until you die. You might still have hit points, so not unconscious, just staggering across the battlefield, flailing with your weapon, one hand clamped over the severed artery that's leading away your life blood.
Regain 1 wound on a long rest, or half level, or trade hit dice for wounds. High level magic, like Restoration or Heal could restore 1 wound.
Adds some lasting consequences to combat that build up over the course of the day. Makes healing magic feel like more of a patch up job than curing any injury. Useful for the DM to explain why an NPCs hold on long enough to tell you a plot point but a quick Cure Wound doesn't bring them back to their feet, ready to explain the mystery in detail.
The grittier variant rule in the DMG to slow down healing and regaining hit dice just slows the campaign, it doesn't make combat deadlier.
There are quick fixes, like making death save failures reset only on a short or long rest so that deadlines builds up over the course of the day. However you might get you Healing Word in every round before you need to make a save.
A harsher effect could be gaining a level of exhaustion each time you drop to 0hp. That might be too harsh though and turn into a quick death spiral. You might get a level of exhaustion right at the start of the day and be wrecked for the rest of the adventure, which isn't much fun.
More complex (but that's what we're here for) could be something like tracking Wounds. You start with Wounds equal to your Constitution score. Each time you drop to 0hp, are hit by a critical hit, take damage greater than 50% (or maybe 25%) of your total hit points, you lose a wound. Once you are below 50% your total wounds, get a level of exhaustion that can't be removed. Once below 25% gain a second level of exhaustion.
Once you hit 0 wounds, your dead, no saves. Or once you hit 0 wounds you are dying but can't stabilise, you just keep making death saves until you die. You might still have hit points, so not unconscious, just staggering across the battlefield, flailing with your weapon, one hand clamped over the severed artery that's leading away your life blood.
Regain 1 wound on a long rest, or half level, or trade hit dice for wounds. High level magic, like Restoration or Heal could restore 1 wound.
Adds some lasting consequences to combat that build up over the course of the day. Makes healing magic feel like more of a patch up job than curing any injury. Useful for the DM to explain why an NPCs hold on long enough to tell you a plot point but a quick Cure Wound doesn't bring them back to their feet, ready to explain the mystery in detail.