The Spirit of Small Gifts

Somewhere in the vast multiverse, there is a post office box. It looks like all post office boxes in all parts of every world, and sits on the corner of any—or possibly every—street. Inside are many levels, inhabited by small spirits whose sole tasks are to ensure that the tiny pieces of every metaphorical puzzle arrive where they are needed before someone needs them. You are one of these spirits. Perhaps someday, you will rise to become a deity.

In The Spirit of Small Gifts, as you talk to your friends about the TTRPG games they're playing, you get to be the answer to the question "Is it reasonable that I'd have ______ in my inventory?" A Spirit of Small Gifts drops small, seemingly valueless trinkets in the mail so that the recipient has them in their pockets when they need them.