- Magic-Users have a -25% earned experience penalty;
- Clerics have a +25% earned experience bonus;
- All classes need 100,000 xp to reach 8th level, plus 100,000 xp per level thereafter.
But for Clerics, I've decided it might be best to introduce a little distinctiveness, to avoid copying the non-OGL progression too closely. Setting Cleric hit dice to 2/3rds level, round up, through 10th level not only makes it distinctive, it means that I can now set the Target 20 attack bonus equal to hit dice in all cases. Also, at 11th level, the Cleric HD progression can switch to 4 + level/3, allowing it to sync up with the by-the-book progression.
As a side note, I'm going to make the default procedure "reroll all hit dice when reaching a new level to determine new hit points", but I will include a note on how to use the method in common use. The way bonus hit points work in the LBBs make it clear that the current common usage wasn't the intended usage; the change came after the switch to different hit die types for each class.