Good Free RPGs?

[Grod_The_Giant]

What would be the most recommended PbtA systems?

Dungeon World, maybe?

You could always check out my system, STaRS . It's designed to be a fairly rules light system, on a similar level to Fate, but without relying too much on narrative-based mechanics. It's also designed to be lightning fast. Resolution is "roll 1d10 and get under your stat," so players don't have to wait for the GM to know if they succeeded. the GM, meanwhile, doesn't even HAVE stats for their NPCs in a traditional sense-- just a health bar, whatever level of "he's got earth magic" you're comfortable with, and notes on what sort of opposed rolls against them are easier or harder than normal.

The coolest thing (in my completely unbiased opinion) is that there isn't really a combat engine--instead, there are general "conflict" rules that you can use to zoom in on any sort of activity where you want there to be a dramatic back-and-forth. (Fate Core sort of does this too, but not as well-- my rules are the best I've seen for fitting environmental hazards and skill challenges into an exciting framework).

There's a pay-what-you-want light version, but if you pick up the full ($10) book there's also an entire chapter about how to extend the rules for different sorts of games and subsystems.