From the back cover:
A Fist Full of Credits
You and your friends are Bounty Hunters travelling across the radioactive wastes of a desolate, mutant infested world to bring a gang of evil desperadoes to justice.
This book contains pregenerated characters and the Waste World Lite rules. In it you will find all you need to play A Fist Full of Credits. it is a complete easy-to-learn roleplaying game. Just add dice and a bad attitude!
From Page 3:
If you already own [the] Waste World RPG then you'll already be familiar with the rules given in Waste World Lite. They are basically a cut-down version of the rules in the main game. If you don't already use the rules for automatic weapons given in the Forceshield and Campaign Pak, you'll find them in here. We recommend you use them since they are faster than the rules in the Waste World RPG.