Combine or keep separate?
The first decision is whether to merge an expansion into the base game's box or store it on its own. Combining is more convenient for setup and saves shelf space, and it's the right call for expansions you always play with. Keeping them separate makes sense for modular expansions you swap in and out, or when the base box simply can't hold any more.
The space hack: expansions in the base box
The single most-recommended way to shrink a growing collection is to store expansions inside the base game's box and retire the empty expansion boxes to a closet — or toss them. A condensing insert makes it work: foamcore or fitted organizers are built to hold a base game plus all its expansions in one box, collapsing several boxes into one on the shelf. Hobbyists call this 'the way' for a reason — it reclaims more shelf space than any clever shelving, and it keeps everything for a game in one place so setup is faster. It's the first thing to try before you consider anything more drastic.
Combining into the base box
If you merge, do it so nothing gets lost or confused.
- Use a larger or adjustable insert rated for the base game plus expansions.
- Keep expansion-only cards sorted or sleeved a consistent way so you can pull them out if needed.
- Check the lid still closes — expansions are the most common reason a box overflows.
- Hold on to the expansion's rules sheet; tuck it in with the base rulebook.
The resale caveat — keep the boxes
There's one real catch to condensing everything into the base box: the empty expansion boxes matter for resale. Collectors want complete boxes, and some expansions go out of print and become hard to replace, so a game with its original boxes is worth more and easier to sell than one whose expansion boxes went in the recycling. If you might ever sell a game, flatten and keep the expansion boxes in a closet rather than throwing them out. This is also the main argument against the more extreme space hacks — cutting boxes down to size, or 'true-sizing.' The community mostly treats trimming original boxes as a mistake: it saves some space but destroys resale value and is widely seen as mutilating the game. Condensing into the existing base box gets you most of the benefit without the damage.
Storing expansions separately
When an expansion lives in its own box, keep it findable and intact. A divider box or a card storage box with labeled sections keeps the components sorted and the small bits from escaping. Label the box clearly with both the base game and the expansion name, and store it right next to the base game so you never go hunting for it on game night.
Don't lose the pieces or the paperwork
Expansions are where components and rules go missing. Keep every expansion's rules with the game it belongs to, bag or sort small unique tokens so they don't blend into the base components, and if you sleeve, sleeve the expansion cards to match the base set so they shuffle in seamlessly and aren't identifiable from the back.