Working on a tabletop campaign. The campaign has a set of 20 artifacts to collect. Because I'm autistic, I'd like to have a naming scheme to tie them together. Like if were 8 I could go with phases of the moon, or 12 they could be named after one of the zodiacs or months or anything like that. However, I didn't realize how few culturally significant sets of 20 there were. I was wondering if anyone else had any ideas?