I have a love/hate relationship with the ideas of critical rolls. On one hand, I love ridiculous tables, things driven by chance, etc.
On the other hand, I often dislike that something can be completely won or lost by a roll alone. I tend to like these sorts of things to be eventual outcomes of a successful plan or a stupid idea. The chance that something can just get a 5% roll, which will happen frequently enough, and maim or murder a character or npc outright is a little too frequent for me.
Because of this I have mostly modified my “criticals” in OSR games to require the person being critted upon to make a saving throw before any effects are levied, and even then I end up using a temporary wound chart.
Here is the section from my own OSR house rules:
Whenever an opponent scores a critical hit on you, and you do not drop to 0 hp or less, make a saving throw. If you fail receive a Temporary Wound. Roll on the chart below:
1. No effect
2. Pained – next roll is at disadvantage
3. Stunned – lose next action
4. Slammed – be knocked prone
5. Dropped – immediately drop unconscious and set your hp to 0.
6. Vacated – struck so hard you vomit, take no action next round
7. Blood in Eyes – you have disadvantage until you can divert the blood flow
8. Ears Rung – you have disadvantage to all WIS checks
9. Feebled – you have disadvantage to all STR checks
10. Swollen – you have disadvantage to all CHA checks
11. Hobbled – you have disadvantage to all DEX checks
12. Dazed – you have disadvantage to all INT checks
13. Numbed – you have disadvantage to all CON checks.
14. Hurt hand – drop what you hold and take disadvantage for all checks using that hand
15. Hurt arm – your arm is unusable until you can repair it
16. Hurt foot – you lose initiative until you can repair your foot
17. Hurt leg – you can only drag yourself until you repair your leg
18. Hurt back – you cannot act until someone can fix your back
19. Wounded – you start losing hp per round until you heal it.
20+. Permanent Wound – roll on the next table
