Upper_Krust
Legend
Hi seasong mate! 
Well you can either use the spell level itself (and treat it as a Spell-like ability);
or take the monsters CR (instead of caster level) and multiply it by half the monsters CR (instead of spell level), then multiply by the Uses modifier.

seasong said:I'm probably missing it somewhere. How are the summon spells broken down in this system?
I.e., what limits are set for a summon monster III?
Well you can either use the spell level itself (and treat it as a Spell-like ability);
or take the monsters CR (instead of caster level) and multiply it by half the monsters CR (instead of spell level), then multiply by the Uses modifier.