My first greeting card RPG? This is Mishaps of the Extra-Planar Interiors of Infinite Storage Boxes (2021), by my pal Derek Kinsman. As the cover says, it is a brief set of rules and a table keyed to making use of things like bags of holding more frustrating for characters (and, hopefully, more amusing for players). Curses and angry interdimensional entities abound.

More tools like this, please!