LA: - and class levels

[atemu1234]

I've always treated monsters with LA: - as basically being incapable of taking class levels, but as a DM, I really want my PCs to run into some unusual creatures with class levels. From DMs who have done this before, what are the risks? I'm still following the CR guidelines given in Monster Manual to go with increasing class levels, but are there any others?

[Doc_Maynot]

LA - just means it's inaccessible to players. And typically it is agreed that CR isn't that great a system to determine challenge (https://www.youtube.com/watch?v=BsMSiVn6vpQ) there are a few alternative CR calculation systems (http://www.giantitp.com/forums/archive/index.php/t-192329.html) that make a bit more sense.

[Karnith]

Take note that the associated/non-associated class levels guideline are not very good. It's especially bad with nonassociated class levels, which frequently lead to deceptively low CRs.

[atemu1234]

Take note that the associated/non-associated class levels guideline are not very good. It's especially bad with nonassociated class levels, which frequently lead to deceptively low CRs.

I tend to treat all classes as being associated, and NPC classes as unassociated, because even monks can be justified for NPC CR somewhat.