I've already Googled video game scripts and all I get are a bunch of "how to write a game story" that are mostly click bait, simplistic explanations. I'm interested in linear action game scripts, open world action RPGs/RPGs in general, FPS's and non linear scripts. Where can I find good samples to study, getting an idea of how they're formatted and written?

Open source games.

Although you will regret it. Even the smallest game is a maze of over 200 scripts that all interlink and depend on each other. The best to do is learn it all part by part.

Flare RPG (the Empyrean Campaign) was finished recently, so that's probably a good example:

http://flarerpg.org/

The IGDA Game Writing SIG has a page where writers have shared some of their scripts, including scripts for games like Guild Wars 2 and Call of Jaurez: https://www.igda.org/members/group_content_view.asp?group=121051&id=421190

Someone also transcribed Half Life's dialogue: https://gamefaqs.gamespot.com/pc/43362-half-life/faqs/29847

Mods are another great source. The best of them rival AAA writing. Download some high quality mods for Dragon Age, Skyrim, Fallout, etc., and open them in the editor to see their dialogue and action scripts.

If you prefer to read your Dragon Age / Neverwinter Nights scripts in a screenplay format, I can suggest a roundabout solution. It requires a paid version of Chat Mapper, though, such as the indie license. Use NWN Module Tools to convert the mod to XML. Then use the Dialogue System for Unity's free evaluation versionevaluat to import the NWN XML into Unity, and export it to Chat Mapper XML. Then import the Chat Mapper XML into Chat Mapper, and export it in screenplay format.

Text games (interactive fiction) and Twine games are also good sources, and they often come with source.

22 hours ago, Tony Li said:

The IGDA Game Writing SIG has a page where writers have shared some of their scripts, including scripts for games like Guild Wars 2 and Call of Jaurez: https://www.igda.org/members/group_content_view.asp?group=121051&id=421190

Someone also transcribed Half Life's dialogue: https://gamefaqs.gamespot.com/pc/43362-half-life/faqs/29847

That's what I've looked at already. Looked as in glanced at. I didn't see the Half Life dialogue. hmm I can check that out. 

I also rarely play mods, like at all. I don't know how many I've played. And of the games you posted in your second answer, Skyrim is the only one I'm familiar with. So I'd go into the other ones blind. Lastly, my laptop won't run the recent version of Unity. I've looked into it. If there's an older one I might try that.

You could always join the IGDA Game Writing SIG and ask writers in the group if they wouldn't mind sharing some of their work.

IIRC some people I know who do story based games write the scripts directly in the game engine's dialog editing GUIs, so the game's content itself is the script and it just grows out from there as more content for the game (audio/visuals/code) is created around the dialog.

I've only worked on two story based games professionally. One had something very close to a film-style script / screenplay, which existed as hard-copy (a giant stack of printed paper), picked up in person from the IP holder... The other one we did it visually, where one wall of the office was covered in storyboard sketches on A3 (Tabloid / Ledger) sized paper, laying out the events of the game.

19 hours ago, Tony Li said:

You could always join the IGDA Game Writing SIG and ask writers in the group if they wouldn't mind sharing some of their work.

I could. But I thought it was a paid membership. Or GDC is. Some game development group I've read about has a paid membership, and its expensive.

18 hours ago, Hodgman said:

IIRC some people I know who do story based games write the scripts directly in the game engine's dialog editing GUIs, so the game's content itself is the script and it just grows out from there as more content for the game (audio/visuals/code) is created around the dialog.

I've only worked on two story based games professionally. One had something very close to a film-style script / screenplay, which existed as hard-copy (a giant stack of printed paper), picked up in person from the IP holder... The other one we did it visually, where one wall of the office was covered in storyboard sketches on A3 (Tabloid / Ledger) sized paper, laying out the events of the game.

Nice. I thought writers would do both. I'm sure they do too. Guessing the writing directly into the engine is more for non linear games? 

2 hours ago, Matthew Birdzell said:

Guessing the writing directly into the engine is more for non linear games? 

It's a terrible practice, period. Makes polishing, editing, and additional DLC more time-consuming than necessary.