Permission to Monetize….

This is not, by any means, a complete list of companies and/or games that permit customers to make money off of gameplay videos and the like. If you’re looking for such a list, I found a couple on
Reddit
and the Yogscast forums (with updated lists to be found on Google Docs/Drive)
Feel free to share any others that you might have found, or to provide additional information on what I have given.

The games or companies I have listed here are only relevant to the games I, myself, play.

Monetization allowed

Company: Humble Hearts/Dean Dodrill
Game: Dust: An Elysian Tail
Permission: Dean Dodrill’s Twitter feed
Notes: While Mr. Dodrill did not specify monetizing within his response, the question presented to him–the question to which he replied, “sure, why not”–did specify it.
I must note, however, that I’ve been hearing rumors that YouTube is… picky, to say the least, about the wording of such permission. It is entirely possible that they would block monetizing videos of his game, even with that permission, if it is not expressed in whatever legal-ese that they prefer.
In addition, he is well within his rights to revoke that permission at any time, and if he does so within the Twitter feed, it would be a tad more difficult to find than if, say, he put up a specific remark on the game’s website.

Company: Valve
Game(s): Steam platform
Permission: Valve’s video policy
Notes: Valve specifically states that commercial use of their games is forbidden, that nobody can charge a subscription fee to view the videos (does that mean I can’t upload my blog to Amazon if I put videos on here? 😉 )… but in the next paragraph, it states that they are fine with monetizing gameplay videos via AdSense and the like. Clearly they see a difference between the two.
For my part, Valve’s permission is not relevant… yet. While many of my PC games run through Steam, I do not have any games created by them. (Portal, I believe, would be an example of such.) It is, however, a useful detail to remember.

Monetization not allowed

Anything made by Nintendo.
I don’t know if that extends to all games on their system or just those specifically made by them.

Still researching

I’ve contacted some of these companies and am awaiting a response; I have yet to get in touch with others.

Company: Bethesda/Zenimax
Game(s): Elder Scrolls series (including, eventually, Elder Scrolls online)
Notes: One of Bethesda’s representatives informed me in an email that they are “fine” with gamers creating and uploading videos of their gameplay, provided the video is taken from legal copies of the game (naturally) and is in good taste (which is, I’m afraid, a personal judgement, but still a reasonable requirement), but that they do not permit commercial use or profiting from such videos.
I was then given the address to their legal department if I wanted to discuss the matter in further detail and explicitly seek permission.
Valve’s policy makes me question the meaning of the phrase “commercial use,” and the only argument I can see about “profit” rather depends on what one could rightly be considered an “expense” in the matter, but I will ask for permission. Even if YouTube’s policy did not require that I have proof of that permission, even if copyright were not a factor, I would still ask.
I’m in the middle of drafting a letter to them for that purpose–I want it to be as near to perfect as I can manage before sending it off–but until I send it and get a response back, I must assume I do not have permission to monetize these videos.
Then there is the question of my videos showcasing user-made mods; do I need permission from each creator?

Company: Sega et al
Game(s): Sonic the Hedgehog, sequels, and spinoffs
Notes: This series is going to be a tricky one, for two major reasons. One is that the series itself seems to be divided up among different companies or different branches, and it is entirely possible that they have different policies regarding monetized videos.
Another is that the series–and my collection of it–exists on multiple platforms. While permission from Valve would allow me to monetize any Valve videos, but not videos of other games played through Steam, Sonic presents the opposite problem: assuming, for sake of argument, that Sega (et al) permitted me to monetize my videos, I could do so if they were played on Steam… but could I also monetize, say, the Nintendo versions, even if Nintendo chose not to grant that permission?
And speaking of the Valve version: one of my games is Sonic Racing Transformed, with the Yogscast DLC. Even if I had permission from Sega, I expect I’d need Yogscast’s permission as well for this particular game.

Company: Square Enix/Sony
Game(s): Final Fantasy series
Permission: Final Fantasy XIV (14) material usage guide
Notes: Square’s policy for FF14 specifically states that commercial use, advertising fees, etc, are not permitted… except as part of partner programs such as those on YouTube. While I do not know if the Amazon Affiliates would qualify as a similar exception (it does not list all such exceptions, just those of certain types), it does look like I could legitimately monetize YouTube videos of my gameplay.
There are a few slight problems, however. One is that it looks like I could monetize my gameplay videos… except I’m not so sure. That permission relates specifically to using “materials” such as text, logos, etc. While it does mention “recordings” in one place, and gameplay footage in another, I see nothing indicating whether this permission is restricted to official gameplay footage (e.g. gameplay trailers that Square has already created and placed on their site) versus player-made footage.
The other problem is that I don’t actually play FF14… and that is the only game in the series that I have found even this much on. I included the link only because it gives me hope, however irrationale it may be, that I could similarly monetize the offline games, but the question must still be put to SE. And to Sony, in the event that I wish to monetize any videos of games that I do not have on Steam.