From publisher's website: First Contact is a supplement to 5150, the original set of sci-fi rules from Two Hour Wargames. First Contact revolves around a rebellion on a small planet where the colonists have decided to break away from their home world. It documents the war between Earth and her first colony, Mars. But what starts out as a local conflict erupts into something larger as the rebels, known as the Sahadeen, receive help from an unexpected source, the ever-expanding empire of Gaea Prime. First Contact incorporates the Earth Force and Sahadeen into 5150. We've documented the three stages of the conflict and have provided six linked scenarios into a mini-campaign. First Contact can be played solo against the game mechanics (or against the machine as we like to call it), cooperatively where all players are on the same side against the machine or competitively against your friends. And it can be played from either side. Ideal for use with the 15mm range of Sci Fi figures from Rebel Minis, First Contact can be used with any figures you may already have. 5150: First Contact is not a stand alone game. You must have 5150 to play.