From this post over at grognardia http://grognardia.blogspot.com/2009/09/no-levels.html I got to wondering what no level D&D like gaming could be like. By "no level" I'm meaning no PC levels, no exp.
Here's some suggestions:
Start with your favorite old-school fantasy rpg change things as below.
Hit Points: PCs and Villains get a number of HP = CON + 1.5 x HD type. So if the class has 1d8 HD and the CON of the PC is 14 we are getting a PC with 26 HP.
A spell using character starts with 3 first level spells if they get them at 1st level normally. They start with no spells if they don't start with spells at first level normally.
The highest number of spell levels a spell-caster can have ready is equal to the PC's primary ability score associated with spell casting. A MU with INT 15 would be able to have a total of 15 levels worth of spells ready. ( maybe 4-1st level, 1-2nd, 1-3rd and 1-6th level spell)
Spells are acquired by tutelage or theft. A Cleric would have to maintain a prayer book of spells.
Spells that do variable damage do a number of dice equal to the spell level.
Class skills/ability checks:
If a class has a skill that requires dice rolls to resolve that are normally tied to levels use ability checks. Roll 3d6 vs a ability for class skills, 6d6 vs a ability when it isn't a class skill.
normal-man/non-fighters- THAC0 20
semi-fighters- THAC0 18
fighters- THAC0 14
Saving Throws- use the scores your original game would use for 4th level characters.