The story behind the creation of IQ-xoxo

Raf Peeters, January 2016

For the new IQ-puzzle I created for SmartGames this year, I wanted to use two very simple puzzle concepts: pentominoes and checkerboard puzzles. One of the strong points for all the games in the IQ-range is that the game rules can be simplified to “fill up the grid with the remaining puzzle pieces”. The hard part for a designer is how to make variations to this theme, without sacrificing the simplicity of the game play.


I think I started this game with the shapes of X’s and O’s in my mind. All other IQ-games I designed so far had circular shapes (balls, rings, cylinders). When making renderings and 3D-prototypes I immediately liked the tactility of these simples shapes. The O’s and X’s have the same function as the white and black squares in a checkerboard puzzle. There should always be an O next to an X in horizontal and vertical direction. On the flip side of each X there is an O. This results in different options for the puzzle pieces that are not symmetrical, because only the O’s fit over the dome shapes of the game board.


In Belgium they use paper and pencil to play a game named OXO, which is similar to tic-tac-toe. So the working title “IQ-OXO” reflected this. But in most parts of the world the word OXO remind people of a brand of soup and IQ-TIC-TAC-TOE was a little too long. And after all, it doesn’t have anything to do with this game, except for the shapes of X’s and O’S. So in the end we changed the name to IQ-XOXO, like in “hugs and kisses”.

I wanted to make an IQ-game with only pentominoes. The IQ-games I did so far were always a mix of puzzle pieces made of 3, 4, 5 and sometimes 6 segments. With the current standard size of these games, I only had the option to choose between a 5x10 grid and a 6x10 grid. The nice thing about the 6x10 grid is that you could use all 12 different pentomino-shapes. But the 3D-printed prototype looked unbalanced, like it was overcrowded for this size of game board. So we choose the 5x10 grid instead. But finding the right combination of pentominoes for the 5x10 grid proved to  be much harder than anticipated. I had to select the right combination of 10 different puzzle pieces that gave me the most possible number of interesting challenges out of 18 different possible puzzle shapes. The number of different sets you have to try is quite high, I can tell you that. 

Most sets of 10 puzzle pieces hardly produced any challenges with unique solutions. Sometimes changing 1 single puzzle piece or changing the position of the X’s and O’s on one puzzle piece made a big difference. After trying out all kinds of different combinations for weeks, I choose the current one. The most limiting puzzle piece is the straight dark blue piece. Because of it’s shape it’s placed very often agains the border of the game board. But all other combinations with 10 pentomino pieces didn’t produce enough interesting challenges. What I also noticed is that some parts of solutions come back regularly. Puzzle pieces often combine with other pieces in the same way, creating some kind of super-pieces. With the final set of puzzle pieces 68 (x2) different packings are possible. So that is why you can find different challenges with the same solution.

I think IQ-XOXO is a very nice addition to the IQ-range of SmartGames. It’s maybe the most straight forward IQ-puzzle so far, but I guess that people who like this kind of puzzle don’t mind. When I started creating challenges, I was afraid that it would be very hard to solve, because of the double sided puzzle pieces. But after some testing I removed a lot of easy challenges and replaced them with harder ones. The right place of each puzzle piece is often easy to find because the height of the grid is only 5 squares and all the puzzle pieces are quite big, especially compared to the other IQ-games. The end result is a puzzle which is similar in difficulty than IQ-Blox, but easier than IQ-Link, IQ-Twist or IQ-Steps.

example of a Starter challenge/ solution of IQ-xoxo

example of a Wizzard challenge/ solution of IQ-xoxo


1) Choose a challenge. Place the puzzle pieces on the board as indicated. 

Watch out! Each puzzle piece has two sides, X on one side and O on the other. Only O’s fit over the dome shapes of the game board.

2) Try to fit all the remaining puzzle pieces on the game board. There should always be an O next to a X in horizontal and vertical direction.

3) There is only 1 solution, which can be found at the end of the challenge booklet.

Website ©2024 Raf Peeters

Products and images: © Smart