1 Siobhan: Have you ever played Millennium Blades?
2 Ishmael: Isn’t that a collectible card game?
3 Siobhan: No no no! It’s a board game about people playing a collectible card game.
4 Ishmael: Wow. The only way you could make that nerdier is if you made a webcomic about it.

Millennium Blades is a real board game, and yes, it's really themed about people playing a collectible card game.

In the (board) game, you play the role of a collector and player of the card game Millennium Blades, which is a (fictional) collectible card game that has been in existence for thousands of years and has had billions of different cards printed over that time. There are phases of the (real Millennium Blades board) game in which you buy, sell, and trade cards to try to make your (fictional) Millennium Blades (card game) deck better, followed by phases in which you play your (fictional Millennium Blades card game) deck against other (fictional Millennium Blades card game) players, in order to win (fictional) tournament prize money, so you can improve your deck more in the next (real Millennium Blades board game) trading phase.

If you think that's an overly meta level of self-referentiality for a game, check out Deck Building, the Deck Building Game.

Who said gamers were nerds??