1-5: Self-harm
1. Disaster (this is gonna leave a mark)
2. Hit an ally or self (random) for max damage
3. Hit an ally or self (random) for regular damage
4. Throw weapon into ally or self (random) for minimum damage
5. Hurt yourself (1d4+level)

6-10: Loss of control (Gives an attack of opportunity unless tumble checks)
6. Knock yourself unconscious + 1d4 dmg
7. Weapon goes swinging (strength check for how far)
8. ?
9. Trip, fall, hurt yourself (1d4+1/feet+1/50lb worn)
10. Trip and (balance check) falls

11-15: Environmental/Item damage
11. Weapon breaks spectacularly and hits someone
12. Weapon breaks
13. ?
14. Weapon gets stuck in environment
15. Weapon hits the in environment (may break something important)

16-20: RP/Safe fails
16.
17. Cramps out (-4 on all checks until fortitude save, DC 16)
18. Gaze out/distracted for the turn (will check)
19. Nothing bad happens
20. Spectacular failure (Accidental success)

GM Notes (Only visible to GM)
Fumble disaster (will leave a permanent mark):
1. Self-harm: Crits self or ally (random) for max damage or deadly situation
2. Loss of control
3. Catastrophic environemental damage (the worst that could happen)
4. RP disaster

Fumble miracle: Reroll and adapt positively as a success