While looking at my blog's statistics, I noticed that I get many visitors searching for slot game implemented in XNA. I decided to dedicate a number of posts to building a simple slot game in Microsoft XNA. I will start from a very simple demo game and ultimately grow the project to a full-featured slot game.

We will be developing a multi-line video slots game. More specifically, our slot game will have 5 columns and 3 visible lines as shown on the game screen-shot.

In this type of slots, there are 9 playing lines and a user can choose which lines he/she wants to play.

The heart of the game is a class, which I have named Reel. This class is in charge of rendering and animating the slot symbols on the screen.

In the image on the left, you can see the texture that we will be using for our slot game. The actual texture is a 800 x 1920 pixel image, which contains 12 rows and 5 columns. Each column corresponds to a single reel and each row corresponds to a stop or position (i.e. the symbol) on the reel. The texture width and height are multiples of 4 and thus we can use the XNA compression to reduce the file size of the texture. The nice looking symbols are taken from Microsoft's Office Clips Online web site.

Our reel will be using a virtual stop table. I will be describing the virtual table in an upcoming part but for now let's concentrate on the visual side of the game.

Each symbol corresponds to a stop on the reel. Let's agree that we call Stop 1 such a position of the reel when the lowest symbol on a column is located at the bottom line.

For example, if we take the first column, its Stop 1 corresponds to a position where the bottom 3 symbols (pineapple, coconut, berry) are visible on the screen. Stop 2 is when watermelon, pineapple and coconut are visible and so on. Thus, Stop 12 will be when the coconut, berry and cherry are visible on the screen. Please look at the illustration below to make sure that you have a correct understanding. 

You can download the source code and play with it. I have also put a compiled version for you to test. Run the application and hit the S key on the keyboard to spin.

Our Reel class is extremely flexible. If you wanted to make a single line slots game, all you had to do is to change the REEL_LINES constant value from 3 to 1.

In the next part we will add some labels on the screen so that we display different information (lines selected, balance, winnings) to the user.

Download the Source Code

Download Compiled Version