What exactly is Kingmaker?

A long while ago, some friends were involved in a game of Kingmaker, which is apparently a module where you make or break your own fortune. Is there anything more to it?

Hex-based exploration and kingdom-building rules built into the adventure path.

It's also been made into a Video Game. The video game, like the Pathfinder Adventure Path it's based on, and very popular.

Here is a link to the pathfinder wiki with some more information on this adventure module.

It is also a video game.

I would include a caveat that the video game is VERY different than the actual module. It plays like a DM who didn't like the module and changed a lot of things to fit to their personal style.

The module itself is an interesting setup though, since as kingdom-building setup is not a common one.

I have DM'd the first two books of the Pathfinder Kingmaker Adventure Path and really enjoyed it, as did my players. There are some little changes the would make it better (much of which is talked about in the official forums for the game), but as-is its still a lot of fun. As others have mentioned, the Kingdom Building side-game is unique and fun, and it's very sandbox. If you or your players prefer something more linear, this probably isn't the AP for you.

How tied is it to the Pathfinder rules?

The adventure path? You could pinch characters, encounter ideas and plot points. The CRPG? Very. Frustratingly so, to be honest... it plays like a mechanical puzzle. You need the right spells, weapons and abilities to deal with certain foes or you hit brick wall after brick wall.

I'm talking about the AP, not the computer game. Just wondering how 'portable' the hex crawling and kingdom building is. Could you use it in an OSR game, for example?

The hexcrawling is very portable I'd say. There aren't really any rules to it aside from however you handle overland travel.

Kingdom building is pretty mechanically heavy, but it is is own system entirely. You could lift the whole system and plop it into a D&D game or something without too much modification.

The AP otherwise would be as easy to convert as any other AP, imo

Hmmm, a hex-crawl, kingdom-building game on Golarion, using SWADE. Makes me wonder.

Forbidden Lands is an excellent hex-crawl game with stronghold building

Oh man, I would play the hell out of that. Honestly I actually like Pathfinder's ruleset just fine, but SWADE is just... it's got that degree of flexibility that lets you make concepts that are harder to fit into some systems. And Golarion is one of the best executions of a Kitchen Sink setting I've ever seen.

Yeah! Running it Friday night, actually...

Oh nice!