Life is fairly easy to play. All you need is a grid or checkerboard and a couple of counters or markers to indicate marked squares. Graphing paper and pencil is also fine for starters to get a sense of how the game functions, but most simulations would be most easily done on a computer. You can download the software from various web sites. For Windows users, download one of the best programs here. And for a great Mac version click here to download. Most programs are free for your noncommercial use, as there exists a plethora of them each with multiple versions on the net, and offering differing levels of functionality. Even writing a program like this on your own in any language should be an interesting task that should not be too difficult.

Life is played on an infinite 2D grid consisting of a plane of cells, whereby each cell can be in either of two states: alive or dead. Those alive are usually marked with a circular marker or stone to indicate a live cell. The game takes place in discrete time steps where certain rules are applied to all the cells simultaneously. Conway’s rules are sinfully simple. Around each cell are eight other neighboring cells whose states determine the future state of the encircled cell; four of which are adjacent orthogonally, and four adjacent diagonally. Here are the rules:

Survivals: Each live cell with two or three neighboring live cells survives for the next generation.
    
Deaths: Each live cell with four or more live neighbors dies from overpopulation, while those with one live neighbor or no neighbor dies from isolation.
    
Births: Each empty cell adjacent to exactly three live neighbors--no more, no fewer--is a birth cell. The cell becomes alive in the next generation.
    

All births and deaths in Life are applied at the same time to all the cells. Each "move" consists of an iteration of this birth death process.

Though the population constantly morphs and changes into various symmetrical patterns, the life cycles generally end up in three different case. In the first, all the cells eventually die out and the board becomes empty. In the second, the cells reach a stable configuration or "still lifes" which cannot change or will oscillate in a set cyclic pattern forever like a blinker. In the third, the cells do not stop moving and continually generate more living cells in the universe like a puffer train.

Conway tested out various numerical combinations for birth and survival rates and chose the rules for Life because of the difficulty in predicting the final behavior of the initial configuation when applying those rules.