Particle_Man
Explorer
I thionk if you just changed the 10 level classes to 20 level classes, giving out the abilities every other level instead of every level, and changing the DC's on some abilities (usually to DC whatever + 1/2 class lvl instead of DC whatever + class level) you won't be too far wrong. If it had a lousy, med, good bab, or bad/good saves, it retains them.
The 5 level classes could go the same way (only now space out every 4 levels) but might not be as fun to do (too many dead levels).
The 5 level classes could go the same way (only now space out every 4 levels) but might not be as fun to do (too many dead levels).