Important to know before starting a subscriber stream on Twitch
Twitch will allow streamers to run subscribers-only sessions to either get closer with their paying supporters or force commercializing their channels. It will be possible for non-subscribers to preview these subscribers-only sessions for up to 30 minutes a day per channel before being prompted to subscribe to continue watching.
This is an interesting move forward as it will allow for streamers to produce exclusive content for those who support them financially. There is, however, a catch to this feature for gaming channels.
Legal terms by publishers and developers
The content you want to produce on your livestream can have a great legal impact if you are not aware of what terms to follow from the different publishers and game developers. To give you a heads-up, here are a few of the more well-known publisher/developer terms to be aware of:
Use of our content in videos must be non-commercial. By that we mean you can't charge users to view or access your videos. You also can't sell or license your videos to others for a payment of any kind.
— Steam: Video Policy
We permit individual players to solicit personal donations or offer subscription-based content while live-streaming games, so long as non-subscribers can still watch the games concurrently.
— RIOT » 2. No commercial projects » Exception 2
We understand that any third party websites have a "free" method to see their video content, as well as a 'premium' membership service that allows for speedier viewing.
For clarity, please note that as long as the website that hosts your Production provides a free method to allow viewers to see the Production, Blizzard Entertainment will not object to your Production being hosted on that site, regardless of the site's "for pay" premium service plans.
— Blizzard Video Policy
EA appreciates the passion that players have for our games, and we're always excited to see the creativity that comes from our community. EA does not object to fair uses of video footage or screenshots on video sharing sites, including YouTube channels that are commercialized, as long as the footage is a version of the game that we have released to the public.
— How to request permission to use EA content
Finally, please do not charge users to view or access your videos. Do not sell or license your videos to others for a payment of any kind.
— POSTING COPYRIGHTED UBISOFT MATERIAL
Generally Take-Two Interactive does not object to fans using materials for non-commercial uses in a manner which does not intentionally spoil the plot for others. "Non-commercial" includes that you don't sell site membership, or use the material to promote a product you sell...
— Policy on posting copyrighted Rockstar Games material
Be prepared for Article 13 in Europe
Please understand these terms are already enforceable and should be complied with. These terms will become even more impactful as Article 13 will come into effect during the next couple of years. You will need these to be public for sites like YouTube or Twitch to be able to publish your gameplay content with ease.
Feel free to bookmark this article for easy reference to the stated sites and if anyone adds to the list in the comments.
"Subscribers Only" Reference: https://help.twitch.tv/s/article/subscriber-streams