GURPS lite.

But really, probably BRP, SW, Mutants and Masterminds, Fate, or Heroquest... mostly a matter of taste.

BRP. (Chaosium's "gold book")

No love for TORG? It was explicitly made to handle multiple genre.  That having been said, I don't know much about the current iteration, just the classic edition.  The big thing is it'll handle scaled things like, say, a Strength score for Tolkien orcs, normal humans, dragons, and super heroes.

Another vote for Savage Worlds.

Although, my personal choice would be Tri-Stat or True20.

True20 especially if your players are 3x or 5e players. They will grok True20 very easily.

I'm not a Savage Worlds fanboy, but it is the generic setting darling RPG right now.

My choice would actually be more rules lite games.  In this case, Tiny D6.   The bad news is you would need to buy all of their various rule books to get a multi-genre game out of cobbling them all together. 

So, maybe Savage Worlds would still be a better choice, even if I don't like it myself. 

Quote from: Godsmonkey on May 10, 2022, 12:30:32 PM

However, Im also a fan of BRP. It's adaptable to pretty much everything as well. Of the two, you would need to choose what level of crunch you want in your game. Savage Worlds leans into pulpish action, whereas BRP has a deadlier vibe to it.

So really, the question is how much crunch, and what kind of feel do you want in your game?

Yeah . . . without knowing more about what kind of system the OP wants, it's hard to make recommendations. Grid based combat and minis? Theatre of the mind?
I generally go rules light with pastiches, and would probably recommend something where disparities in PCs "power-level" are mitigated by meta-currencies or narrative power.

A couple examples from designers I know, and carry on my marketplace:
Spark (generic, with world creation advice/mini-game)- perhaps with it's specific implementation of Sig: Manual of the Primes as a guide. It's a homage to Planescape, and mechanically puts PCs with a heritage like "Fire Giant" on equal footing with PC whose is a "human garbage man." They'll certainly do different sorts of things in the game, but they have equivalent ways to contribute to the . . . narrative.

Screenplay can be used to model . . . pretty much anything, as long as you like making it feel like a TV show / movie.
It's more trad and less story-gamey than it may seem.
One specific implementation is "High Plains Samurai" which has a free 82 page quickstart and is a pastiche of gunslinger, samurai, barbarians, and steampunk factions. https://highplainssamurai.com/#about

I use these for everything:

https://ogc.rpglibrary.org/index.php?title=OpenD6

Fate was mentioned, but I'll suggest Fate Accelerated Edition for less crunch.  Since everything is aspect driven, it's easy to describe various elements and attributes and still have them be able to work within the same game mechanics.  You can get similar mileage out of the PDQ Core system if you're not a fan of Fate/Fudge dice.

Amber/Lords of Gossamer and Shadow has been mentioned as well.  But, the PCs for Amber at least tend to be at the demi-god level and that may not be a good fit for your setting.

Since you mentioned cinematic action, take a look at Wushu since its core mechanic is literally using cinematic actions and descriptions to build your dice pools.

http://danielbayn.com/wushu/

GURPS.