TTRPGs: Help me orient myself among D&D, Pathfinder, Starfinder, and Traveller. I've played D&D and Traveller, but I don't understand the others.
Here's how these systems relate to each other:
D&D (which you know) is the foundational fantasy RPG - class-based, level progression, d20 system in recent editions.
Pathfinder is essentially "D&D 3.5 continued" - when D&D moved to 4th edition, Paizo created Pathfinder to keep the 3.5 ruleset alive with their own improvements. It's more complex than modern D&D, with tons of character customization options, feat chains, and tactical combat. Think of it as D&D but with more mechanical depth and crunch.