(Psi)SeveredHead
Adventurer
I'd be careful, some classes are more powerful as NPCs.
For instance, NPC spellcasters are almost always prepared for combat, with high magical ACs. Many published adventures have spellcasters who heard you from another room and have already cast 9 spells on themselves (I've counted). Prepared, and since they just cast their spells, they have little need to worry about defensive spells running out during combat. Furthermore, NPC spellcasters can cast all of their spells in a combat, whereas your PCs will need to save some for later. (This applies to psions as well).
Druids are even more dangerous: Which of those squirrels is the druid, spying on you? No DM forces their PCs to make Spot checks to see "suspicious" squirrels. NPC druids often have more animal companions as well.
Some psions will be very dangerous: any that use polymorph self and that also have mind-control or ranged attack powers. Picking powers that don't highlight the psion (eg mass concussion covers the area in slime, but who done it?) will really hurt the PCs.
Monk NPCs will be a little more useful (=dangerous): They can use all of their stunning attacks right now, and not worry about later.
Barbarians are less useful: They are only going to rage once in combat anyway, so you might as well give them four levels of fighter and specialize.
For instance, NPC spellcasters are almost always prepared for combat, with high magical ACs. Many published adventures have spellcasters who heard you from another room and have already cast 9 spells on themselves (I've counted). Prepared, and since they just cast their spells, they have little need to worry about defensive spells running out during combat. Furthermore, NPC spellcasters can cast all of their spells in a combat, whereas your PCs will need to save some for later. (This applies to psions as well).
Druids are even more dangerous: Which of those squirrels is the druid, spying on you? No DM forces their PCs to make Spot checks to see "suspicious" squirrels. NPC druids often have more animal companions as well.
Some psions will be very dangerous: any that use polymorph self and that also have mind-control or ranged attack powers. Picking powers that don't highlight the psion (eg mass concussion covers the area in slime, but who done it?) will really hurt the PCs.
Monk NPCs will be a little more useful (=dangerous): They can use all of their stunning attacks right now, and not worry about later.
Barbarians are less useful: They are only going to rage once in combat anyway, so you might as well give them four levels of fighter and specialize.