A 3House set includes 45 pyramids as shown below. It is a combination of three Treehouse sets. Since each Treehouse set also includes a 5×5 grid, a custom die, and a standard six-sided die, these materials may or may not be required by games marked as playable with "3House".
The term first appears in the 3House booklet, which has three games that use three Treehouse sets. Andy Looney has described the 3House set as a "sweet spot," an ideal number of pieces for many of his game ideas, and he has designed several games around that set, including Martian Chess, Black ICE, Zark City, World War 5, and at least two unannounced secret projects.
See Also: Games playable with a 3HOUSE set.