How much Damage would a Lightsaber do in D and D?

[Callos_DeTerran]

Welcome to the wonderfully ridiculous world of hit points. A sword that does 1d8 points of damage can cut an unarmored man in half from shoulder to hip in the real world, but in D&D that only works on first level characters with small hit dice.

Not that ridiculous considering hit points don't just represent how much hurtin' someone can take but their energy to dodge, evade, parry blows, etc. I've always seen massive amounts of hit dice as the character evading/dodging attacks down into like...the twenties or so of hit points when they'll actually start being injured.