Get one of the published adventures. There's one set on a remote space station, something like that is good to start with since there are far fewer things to keep track of and fewer options compared to a city or large hab. Then just sit down and play the game. You'll learn along the way. As a GM, making the NPCs come alive is key. Make a psych profile for your NPCs. Decide in advance how they will react to being flattered or threatened, etc. This will make them seem like real people with depth. Here's a short list I use for inspiration: Reaction to: Innocent approach Suspected/accused Found out Tempted Threatened Violence Treated well Criticized Opportunity to act Reacts with: Panic, defensive, lashing out, suspicious, withdrawal, shifting focus, violent, submissive, aggressive, cool, deadpan, constructive, manipulative, lying, denial, self-deceiving, weasel, bartering, three steps ahead The reaction pattern to stress is generally: Freeze, flight, fight, in that order. And only the very agitated stay in losing fights. I try to describe NPCs with these 4 points to make them clear and memorable: Physical Status Presence Defining trait I typically don't stat NPCs up much beyond that, just stuff like Good: Combat, Stealth. Bad: technical stuff. Then I assume everything else is average and assign numbers on the fly based on those notes. It is much faster both in preparation and in play (looking through NPC skill lists to see if he has 50 or 60 in a given skill is not just pointless it wastes time). Speed and improv is MUCH more fun than accuracy for the players. Let players shine. Beating them up and challenging them is fine when it is on the path to letting them shine, and shine like they want to shine. Enable them. That's your goal as a GM. You're an entertainer. Don't ruin their day, their toys, or make stories so complex they can't figure them out (the measure of a good puzzle is how they can figure it out, not how difficult it is). Try to make your players' suggestions work instead of expecting them to discover the solution you thought up. Never be afraid to retcon. Often you just have to roll with your or the players' mistakes, but if something is getting out of hand, just say so and change it.