InThat Old Wallpaper, you attempt to recover the wall of a house with wallpaper, matching as many patterns as you can.
In the game, a number of locations are available where wallpaper cards will come up for grabs. Each turn, players simultaneously choose a location, and if they're the only one to pick a location, they get the card or cards in that location. If you choose the same location as someone else, each of you receives a "hazy memory" card that features a wallpaper pattern along only one edge instead of along all four edges.
When you receive regular wallpaper cards, you must add them to your other played cards immediately, ideally matching the pattern halves to create a complete pattern. Patterns come in four colors, with each color having two sizes. A wild pattern is also available, which seems kind of weird, but so be it. To end a turn, deal a new wallpaper card to each location, which means that some locations will likely have more cards than other ones.
At game's end, use your hazy memory cards to complete patterns on the edge of your wallpaper, then score for each color of pattern. The score of a pattern is the number of large symbols of that color multiplied by the number of small symbols, so if you don't have at least one large and small symbol, you score nothing for that color!