Elder-Basilisk
First Post
One thing that's worth noting in the summon monster lists is that different creatures have dramatically different capabilities that are not necessarily reflected in their CRs.
For instance, the Celestial Unicorn (monster Summoning VI) may be weaker in combat than the Celestial Dire Bear but the unicorn can detect evil, neutralize poison (1/day), cure light wounds (3/day), and cure moderate wounds (1/day). Those spells are not normally within the capabilities of a wizard and are consequently a very valuable asset for a wizard (valuable enough IMHO that it's worth summoning a celestial unicorn to get them). Similarly, the Avoral Guardianal (monster summoning VII) is certainly not a match for 1d3 Celestial Dire Bears in a straight up fight but has True Seeing at will and a number of other useful spell like abilities (and the capability to Lay on Hands like a paladin). The last time I played a high level character (14th level sorceror), he summoned a guardinal on several occasions simply for the use of its True Seeing. A number of devils have animate dead at will which is a very valuable asset to any evil summoner if they are available at levels equivalent to their CR.
Consequently, I would be cautious about allowing any creature of CR X to be summoned by a summon monster spell Y. The spell like abilities of creatures can much more useful than the creature's CR would indicate (particularly if, like an Ossylith's Animate Dead ability, it bypasses the need for expensive material components).
For instance, the Celestial Unicorn (monster Summoning VI) may be weaker in combat than the Celestial Dire Bear but the unicorn can detect evil, neutralize poison (1/day), cure light wounds (3/day), and cure moderate wounds (1/day). Those spells are not normally within the capabilities of a wizard and are consequently a very valuable asset for a wizard (valuable enough IMHO that it's worth summoning a celestial unicorn to get them). Similarly, the Avoral Guardianal (monster summoning VII) is certainly not a match for 1d3 Celestial Dire Bears in a straight up fight but has True Seeing at will and a number of other useful spell like abilities (and the capability to Lay on Hands like a paladin). The last time I played a high level character (14th level sorceror), he summoned a guardinal on several occasions simply for the use of its True Seeing. A number of devils have animate dead at will which is a very valuable asset to any evil summoner if they are available at levels equivalent to their CR.
Consequently, I would be cautious about allowing any creature of CR X to be summoned by a summon monster spell Y. The spell like abilities of creatures can much more useful than the creature's CR would indicate (particularly if, like an Ossylith's Animate Dead ability, it bypasses the need for expensive material components).