Uncommon and Rare Summons

[Perpdepog]

So I've been thinking on the fact that summon lists require that the summons be Common creatures, but also that a lot of creatures I like for whatever reason are Uncommon, and sometimes Rare. This led me to the idea that it could be possible to hand out access to an Uncommon or Rare creature for summoning to a player, or to ask the GM if it would be possible to take one or to somehow gain access through the game's story.

My question is, are there any really obvious no-no summons that it would be wise to be on the lookout for? Both for myself if/when I run a game and get asked this question, and for anyone else in the same boat. I think it'd be really neat to curate a summon list through adventures and give a player more investment in their character, but I also have flashbacks to the tangle that PF1E summoning can be.

Also, just for fun, are there any creatures for either thematic or mechanical reasons that you'd like to poach as a summon, if possible? Some of the more thematic undead come to mind for me, like demiliches and kurobozu. Summoning clockworks would also be fun times, as would golems, though I know the books specifically advise against those.

[Darksol the Painbringer]

Depends on the creature.

As a GM, I'd probably let a player summon an Uncommon or Rare creature if they have either encountered it and/or have spent a good amount of downtime as well as some "Recall Knowledge" checks. After all, Summons in-lore are explained as being carbon-copy manifestations of creatures, and not the summoning of an actual creature, conjured after an offering given to the relevant plane it's essence was drawn from.

Of course, I also wouldn't let players simply sift through the Beastiary finding a creature that has XYZ ability for them to exploit, and I would expect a reasonable in-game purpose behind the character wanting the ability to summon such a creature. I mean, the Summon rules do a pretty good job of mostly removing those shenanigans, but I imagine that like much of the rest of the book, it's not ironclad and there are exceptions.

[Castilliano]

Some iconic, somewhat common to encounter creatures are Uncommon because they would shut down certain opponents if they could be summoned, i.e. Golems which are in so many wizard lairs.
Others simply break the normal power curves, i.e. Quicklings, which aren't so powerful, yet have a speed that could be exploited (for its level at least).

Might want to consider tagging on an extra level requirement like Uncommon creatures count as Level +2 (to guarantee they're at least one spell level higher). And check for shut down abilities or other strange curve-breakers.

[Elfteiroh]

I personally let my players gain access to summon uncommon+ creatures if they befriend it or successfully analyze one using a skill check, often Medicine or an appropriate skill (depend on the creature and the player character) and a certain amount of time (this depend on the creature, low-level ones I ask for a couple of hours, a very rare and powerful creatures I might ask for a bit of downtime).
I have yet to encounter a problem.

[Alchemic_Genius]

So, I think it's worth noting that rarity is subjective; one outright canon example is thw dwarven clan dagger; it's uncommon outside dwarf society, but so common in it that you start with one just for being a dwarf.

It seems reasonable to talk with your dm about accessing uncommon/rare summons, especially if it's im character; I'd probs let a player summon an uncommon creature of they discovered one or did research; I'd also allow it if, say, the storm druid was a specialist in elementals, I'd let them summon uncommon and even rare elementals without a fuss. That said, I'd also let my players summons troops so ymmv