Lucky Houses are slot machine minigames run by Sprixies in Super Mario 3D World and Super Mario 3D World + Bowser's Fury. They can appear in every world except World Mushroom, World Flower, and World Crown, with the Prima guide for Super Mario 3D World mistakenly claiming that World 1 does not have a Lucky House.
After the player completes levels a certain number of times in a world, a Lucky House appears and can be entered like a standard level. A Lucky House also appears in the locomotive's cabin in the Coin Express level. The minigame inside revolves around hitting all four Slot Blocks to match Fire Flowers, Super Leaves, Super Bells, Double Cherries, or Boomerang Flowers to be rewarded with coins. The music that plays is a cover version of Super Mario Bros. 2's character-select theme, and the Slot Blocks cycle their images to the beat of this music.
Depending on the number of icons that match, the numbers of coins rewarded are as follows:
- No matches – 10 coins (1-UP if the player has between 90 and 99 coins)
- One pair – 100 coins (1-UP)
- Two pairs – 200 coins (2-UP)
- Three of a kind – 300 coins (3-UP)
- Four of a kind – 777 coins (7-UP, or 8-UP if the player has between 23 and 99 coins)
- Super Mario 3D World Prima eGuide