Is it true that video games pay for High Rating, on Gamespot, Xplay, and others.?

I personally believe that some sites do give better scores because they get paid to do it. But everyone has different opinions on what makes a game great. So if a game gets a high score from x-play, it's possible that the reviewer really likes the game.

I don't think those sites you listed give better scores for pay, but I do think that some of the games they reviewed isn't the complete game or the final version.

It's not impossible. The idea is that a bad review would mean a company won't send advanced "review copies" making it harder for the reviewer in question to do their job. X-play, when it was still on, at least, PROBABLY didn't fall into this; I remember seeing a video from Adam Sessler where he was very offended when someone accused him of exactly this, and he took it as a personal insult.

Short version: it probably DOES happen, but it's certainly not an industry-wide thing.

Xplay is dead but ya quite possible can't see how assassins creed and cod do it every year and have high ratings and some of the beat games get lower ratings then what they deserve

I would assume that a lot of them do. But who knows? Wouldn't you if it influenced your career?