The 1st edition, released by R. Talsorian Games, Inc. in 1988. Based on 'Friday Night Fights' combat system, which uses a d10 to resolve combat.
It also used a d10 to resolve skill checks which could be 'opposed' or 'unopposed'. 'Opposed' rolls made your target a 'roll off against' your target, whereas an 'unopposed' roll just defined a set target number to attempt.
Several Supplements were released before the revised second edition came out.