An expansion is a purchase with prerequisites. Start with the exact base game you own: publisher, edition, language, and region where relevant. Then check what the additional box changes and which components it expects you to already have.
What to compare
Compatibility
Look for an explicit publisher statement about your edition. Similar box art, matching titles, and a seller saying compatible are not equivalent to a supported combination.
What it adds
Separate more players, more scenarios, replacement components, and new systems. An expansion that adds choices may also increase teaching and setup.
Complete contents
Check whether the item is a base game, expansion, accessory, upgrade, or bundle. Confirm which decks, boards, and tokens are included in that specific listing.
A detail worth checking
Avoid purchasing an expansion to solve a problem it does not address. More content will not necessarily shorten play, improve a two-player mode, or make a difficult teach easier.
Make your next session easier
Write down your base edition before shopping. Keep a photo of its copyright or product information and compare it with the publisher compatibility guidance.
Check exact edition compatibility →
