Alternate undead turning mechanic
by Cab DavidsonSpitballing here...
The chance of turning undead is always 9 on 2d6, +1 per HD of the undead creature, -1 per level of experience of the cleric. So a 3rd level cleric turning a 4hd wraith needs to roll 10 (10 +4 for the wraiths HD -3 for the clerics level).
Then you set how many you need to make the roll by to progress from a T to a D, to a D+, to a D#, depending on this you resolve as turning 2d6HD or destroying 2d6 to 4d6HD.