seasong said:
For the constant enhancement, if you wanted something a bit more complicated, you could have it in levels; each level reduces the die type by one step, and adds +2 to the damage. Each level costs +1. Can not exceed the die type.
So a 1d10 sword would stage like this:
1d8+2 (+1 enhancement)
1d6+4 (+2 enhancement)
1d4+6 (+3 enhancement)
1d2+8 (+4 enhancement)
1d0+10 (+5 enhancement)
A 2d6 sword would treat each die separately:
1d6+1d4+2 (+1 enhancement)
2d4+4 (+2 enhancement)
1d4+1d2+6 (+3 enhancement)
2d2+8 (+4 enhancement)
1d2+10 (+5 enhancement)
1d0+12 (+6 enhancement, and epic)
Er...with due respect, no one would go for these.
Considering that a d10 sword does average damage 5.5, a simply +5 weapon will do average damage 10.5- not to mention also have a +5 to hit and +5 to overcome DR and sundering etc.
Personally, I think that the bonus equal to one-half of the average damage (rounding down) would probably be appropriate, so it would pan out roughly like this:
d3 (average damage 2)= +1 enhancement
d4 (average damage 2.5)= +1 enhancement
d6 (average damage 3.5)= +1 enhancement
d8 (average damage 4.5)= +2 enhancement
d10 (average damage 5.5)= +2 enhancement
d12 (average damage 6.5)= +3 enhancement
2d6 (average damage 7)= +3 enhancement.
It's not brilliant, and you'd be probably better off going for a straight enchanted weapon and sinking the to hit bonus into Power Attack (exception: d6 and d10 weapons, where you are 0.5pts better off) and even for those weapons where you do gain slightly, it's slightly inferior due to DR, sundering and the like.