Copyrights around video games videos are complex. If I want to create and post tutorials for a video game on YouTube (specifically Minecraft), do I need to have a partnership with a YouTube Network?
For Minecraft you don't need to be on a Youtube Network.
Mojang says you can monetize your Minecraft Youtube videos.
Even if you use the game's music in it (however you can't use the music outside the video).
The Minecraft EULA says:
If you upload videos of the game to video sharing and streaming sites you are however allowed to put ads on them.
And the Mojang brand guidelines says:
You are allowed to put footage of our game on YouTube or any other website. In fact, we like you doing so. ... ... you may make money using your videos of our game by, for instance, through ad revenue, as long as you also add your own unique content to the video, such as audio commentary.
It depends entirely on the policies of the game manufacturer and what they tell Youtube to do. Some game makers claim copyright over any content produced using their game. Some do not allow any video to be posted, some allow only videos from certain networks, some allow videos from anyone as long as they aren't monetized and some allow anyone to post videos regardless of monetization.
We can't speak to the policy of any particular video game maker. You would have to inquire with them what they consider to be allowed or you could simply make a video and post it and see if it gets a take down notice. There is no blanket YouTube policy that I'm aware of though, they just take down content if a take down request is submitted. (They also do have some automatic filters for detecting music in clips that have previously been taken down.)