Even if it is not real, It can be summoned

>>55291918
You cannot summon something that doesn't exist.
Perharps you could use some kind of collective energy to create a creature. But it wouldn't be exactly summoning...

>>55292257

I don't see why not. The world implies existence when we use it. Once you exit the context of our world it has room to be much more flexible.

>>55293007
OP here, I was thinking of maybe using hte collective Id/unconscious to create/summon entities.
Like say summon something based on a urban legend. Kinda pulling a nyarlthotep from Persona

>>55293144
What about doing something that's almost the opposite? I recall reading a cosmic horror short story where you could summon an eldritch abomination version of just about anything. "Santa Clause" may not be real, but you could try to summon "a magical man in red with twelve reindeer servants pulling his sleigh," and something like "the King in Red" might be able to attach itself to enough of those concepts to be considered a valid fulfillment of that summoning.