People get mad when I use the word ludeme because it’s so fancy and technical but game designers, you got to learn this one.
A ludeme is a component in a game. It can be a card, a playing piece, or even a rule or something you do in the game. The jack of diamonds is a ludeme. So is playing a card to a trick.
A ludeme can be in a board game, a TRPG, or even a video game.