[Zed]

(using AD&D 2nd Ed as reference)

In the olden days, damage rolled was factored in mitigation (DR in GURPS). Armor represented both total glancing hits and those hits that were dead on but too weak to penetrate. The damage roll mechanic was supposed to account for some of the remaining mitigation.

A backstab was supposed to be a targeted attack where the victim is 'surprised' and cannot react to the attack and it is hitting his 'chink in the armor' and piercing something he finds useful to stay alive with (vitals).

The weapon choice had to be something light, stabby, easily concealable and useful at close quarters (presumably while the other hand covers the mouth or throat to stifle any screams of agony).

The thief's weapon selection in the olden days was limited to a short list of pointy weapons for the afformentioned backstabbing or club-like weapons for less leathal mugging and civilized criminality. The thief class could not learn to effectively use other weapons.

~Zed