DC 12 + enemy's attack bonus keeps the hit/miss ratio the same as if the attack was rolled by the DM.
Originally Posted by nolifeonline
DC 21 + attack bonus keeps the hit/miss ratio the same.
Simple example: 19 AC and +5 attack bonus. The attacker must roll a 15+ to hit (assuming tie goes to the player always). That's 6 numbers, or 30% of the time, that he hits.
The player rolls 1d20+19 vs 12+5. He only fails on a 1, so the attack hits on one number or 5% of the time.
If the player rolls 1d20+19 vs 21+5, he fails on 1-6 (assuming tie goes to the player), or 6 numbers and 30% of the time.
I don't think it's a worthwhile system, though. The DM rolls dice faster than the players, so it would significantly delay the monsters' turns and prolong battles. Furthermore, rolling the dice isn't what's fun in D&D - doing
things is fun in D&D. It just so happens that rolling dice is heavily correlated to doing things. Adding unnecessary dice rolls for not doing things wouldn't help anything.
That said, an argument could be made for beating saves. For example, when you cast a spell, it's like your attack. Perhaps it's justifiable that you roll DC+1d20 vs save+21 because you are on the offensive.