As well as the Warhammer 40,000 book, there are a few other items you will need while you are playing. For a start, you'll need two or more players, with a selection of miniatures to represent their forces and a battlefield for them to fight over. Any firm, level surface will do, such as a tabletop or an area of floor – most kitchen tables will do fine! It's a good idea to protect the table from scratches and chips with a blanket or cloth. Some players use a special gaming board made from chipboard on top of the table to extend their playing area. To complete the battlefield you should try to obtain some terrain such as hills, fences, ruined buildings, jungle or woods. Terrain, whether you made it yourself or bought it, adds realism to your battles and gives armies something to fight over or use as much needed cover from enemy fire. You can find out more about armies and battlefields in the Battles Book.
As well as players, armies, a battlefield and terrain there are a few other things you'll need when playing. For troop movement etc, you will need at least one measuring device marked in inches (such as a ruler or retractable tape measure). All distances in Warhammer 40,000 are in imperial measurements.
You will need some ordinary six-sided dice, and a Scatter dice will also be useful. Finally, a pen and some paper can be handy for noting down damage to vehicles, casualties on units and other details that will crop up during a game.