Back in the day, I'd pick up various RPG books and try to learn the system. Some I figured out pretty well, while others remained a mystery. Only a few ever made it to a game table, mostly because a lot of people are hesitant to try something new that doesn't have "D&D" on the cover. Interestingly, except for the various iterations of D&D, almost no system I've played had the same mechanics. I've done the d20 D&D model, the AEG d10 model for L5R, the Shadowrun d6 system, the Pinnacle Deadlands system, and a crazy 2d6 beer and pretzels RPG*. Nowadays I like systems that give a lot of leeway to the GM, rather than those that are tightly bound (D&D 3E/4E, Pathfinder).
*For those who care, nothing was out of character and everything single thing required a die roll. If you ever rolled snake eyes, you died, but character creation took less than 2 minutes. It was really interesting to see who killed you more... the DM or snake eyes!
*For those who care, nothing was out of character and everything single thing required a die roll. If you ever rolled snake eyes, you died, but character creation took less than 2 minutes. It was really interesting to see who killed you more... the DM or snake eyes!