The Treehouse is a part of playground equipment added in The Sims 3: Generations and The Sims 3: Town Life Stuff. There are four types of tree houses: Kid's Clubhouse, Sci-Fi Hideaway, The Princess and The Pauper Castle, and Sunny Bungalow Clubhouse that came with Town Life Stuff. Treehouse is considered a rabbit hole as the inside of it is not visible, though Sims can enter it.
- Children can perform various interactions with the tree houses, including sleeping in them.
- Teens can hang out in the tree houses, or sleep in them.
- Children can restrict which gender is allowed in the tree house.
- Children can pull multiple pranks in the tree house, such as tip water over the victim's head.
- Young adults, adults, and elders can WooHoo in the tree house, although when doing so they may receive a splinter (Then get the negative "Splinter" moodlet).
- Imaginary Friends can come up with their friends.
There's a 50% chance Sims will get splinter while WooHooing in the treehouse. Unlucky and Clumsy Sims have higher chance to get splinter (87.5%) while Lucky Sims have lower chance (0.25%). When Sims try for baby in the treehouse, there's a chance that the baby will have one predetermined trait based on the type of the treehouse, providing the players are unable to choose the traits when the baby is born.
- The Princess and The Pauper Castle: either Snob or Diva[TS3:ST]
- Sci-Fi Hideaway: either Genius or Eccentric[TS3:A]
- Kid's Clubhouse and Sunny Bungalow Clubhouse: either Loves the Outdoors or Adventurous[TS3:WA]