I first reviewed Spot It! more than a decade ago, and I still like it.

Each of the 55 cards in the round deck depicts 8 various-sized symbols such as an anchor, baby bottle, ice cube, zebra, heart, moon, cactus, and ladybug – with a total of 57 objects in all. Take any two cards, and only one item will match between them. The algorithm that was used to create the deck is genius and mindboggling. It is an example of a branch of logic called combinatorics and was written up in a Smithsonian Magazine article.

The matching items will almost always be of different sizes and two or more items on each card will have similar coloring, such as a snowflake and snowman, which can slow down your spotting, if you are going for speed. That’s arguably only important when playing with a partner, because the first one to spot the match in the two cards turned over gets to keep them. But it can also be played alone, more slowly, which is better for many of us. Several variations are also possible.

For example:

  • Name all the items on each card that are the same color. The choices are red, green, purple, blue/white, black or black/white and yellow/orange. They all have a total of 8 objects that are that color except yellow/orange, which has 16.
  • Find items that belong together such as the sun and moon, an ice cube and igloo, an eye and sunglasses (or sunglasses and the sun). There are dozens of possibilities and often more than 2 things within categories, such as hot things, cold things, food, or symbols related to writing (question mark, OK, and exclamation point).