Here's a hit location system a friend and I designed years and years ago (about 1988).
The idea is that instead of having specific hit location tables for each monster, the DM imagines a square area in front of each figure representing the possible areas they could strike. When a hit is rolled, the location is determined by rolling for the type of weapon (1-handed, missile etc.) and the using that on the appropriate hit location display. The DM then makes a subjective call as to what specific part of the target has been hit. With higher skills, characters had the option of adjusting the hit location die.
Initially we had a RuneQuesty system for assigning hit points to locations but after seeing the system in Macho Women With Guns, where hit location adjusted the damage dice (e.g., from d6 to d8 or d3), we switched to that.
Hit Location Tables (d20)
| Area | 1-handed
or 1-edge | 2-handed
or 2-edge | Thrust | Missile |
|---|
| 1 | 1 | 1 | 1-2 | 1-2 |
| 2 | 2 | 2 | 3 | 3-4 |
| 3 | 3 | 3 | 4 | 5-6 |
| 4 | 4 | 4 | 5-10 | 7-10 |
| 5 | 5 | 5-7 | 11-12 | 11-12 |
| 6 | 6-9 | 8-11 | 13-14 | 13-14 |
| 7 | 10-11 | 12-13 | 15 | 15-16 |
| 8 | 12-16 | 14-15 | 16 | 17-18 |
| 9 | 17-20 | 16-20 | 17-20 | 19-20 |
