I think if you are a writer, you will be best off focusing on writing and licensing your successful work for use in video games if what you care about is money, creative control, and prestige. If you are just work for hire, the games industry is not like the screenwriter racket -- writers for TV and movies are highly paid, whereas games writers are paid poorly. The best you could hope for would be to figure out some way to get yourself a stock options from the big corporations like EA or Activision as part of your pay.
This is probably one of the reasons why so many of the 'big name' writers have faded from the scene over time. Few games companies have been able to generate their own 'milkable' creative IP. Take something like Planescape for example. It was a licensed IP, with the dialog worked on by work-for-hire writers who don't hold the copyrights. From the writer's perspective, being someone like George R.R. Martin is great: not only do you get royalties from book sales, but incredibly lucrative licensing contracts from multimedia companies. It's pretty clear also that many technical companies are so focused on the technical aspect of entertainment that they are not that good at growing the value of an IP. The typical result of a technical company like a game studio starting their own art-driven IP is neglect and mediocrity -- see something like Anthem as an example.
Being a great creative in a work-for-hire situation is actually awful and a bad long term career move. Think about the guys who came up with Elder Scrolls. Sure, they probably got shares in Bethesda and became fairly wealthy as a result. But if they had owned the copyrights related to Tamriel, they would be gazillionaires instead of just millionaires. It's the ideal situation for the corporation (they own ALL the rights and don't have to pay licensing fees to do absolutely anything), but very bad for the individual creative. Some of the big writers / artists like Chris Metzen got rich through founding stock and other compensation. But I think anyone trying to be a creative in video games should be a writer first rather than seeking to be a dialogue-writing wretch. This is a time in which, due to politics and other issues, US corporations have a lot of issues creating compelling art. Most of Game of Thrones sucks past the first few books, honestly, but there's a reason that HBO had to pay GRRM tons of money to license the books -- they could not come up with anything better internally.
The reason corporate-owned IPs tend to decay in creative quality is related to these incentives. Dragon Age 1 had some good creative ideas, judging it as fantasy schlock entertainment. EABioware owns the IP -- not any star writer who feels real ownership over the IP because he actually owns the IP. The sequels are creatively driven by corporate committees, which tend to be notoriously bad at producing good art. The writer in such a creative process is just a chump who is paid less than the technical talent and less than the business executives and has to contort the creative to match the technical and marketing requirements set by the product rather than the other way around. Compare this to a writer who is the licensor, who is in a position of power and may be paid more than most of the people involved in implementing the creative vision. Corporations hate this because they have to pay out the nose for it and have to make all kinds of accommodation for the auteur, who has legal leverage over the entire process. Corporations prefer the 'boy band' model in which they own the rights to everything and all the creatives are just for-hire.
