A lot of people tend to get excited about critical hits, but at the same time, with small hit point totals, dealing huge amounts of damage can be problematic.
To accommodate this, here is an alternate approach to critical hits and fumbles.
On an attack of a natural 20, roll below:
1: Foe pushed, knocked backwards or knocked down
2: Armour dropped or damaged
3: Foe stunned
4: Enemy weapon destroyed
5: Additional attack
6: Additional damage
7: Drop equipment
8: Temporarily immobilized
9: Injury inflicted
10: Character knocked out or incapacitated.
On a natural 1, simply treat it as the enemy getting a critical.
You can adjust rules effects, either on the fly, taking creature and character types into account, or you can have them more regimented.
Pushing a character will generally knock them out of their position. Depending on the battle area, that could be problematic of course. A prone character would have a hard time attack (-2 at least, depending on weapon), and be an easy target in melee (+2 to hit). They'd be extremely difficult to hit with a missile though.
Armour being dropped or damaged should generally impact shields first, and armour second. Usually a 1 point penalty in armour class will suffice.
Being stunned would generally be one turn unable to act, while an immobilized character has gotten stuck on something, tripped but retained their footing etc.
Additional damage would be 1D6.
Let me know what you think!
Another article will follow tonight, once my son's playdate is over