ur right in mk1 its raiden but for some reason its rayden in home version i just noticed so i dont know

I think it had something to do with TradeMark/CopyRight issues. I'm not too sure about that though.

copyright issues or something. anyways I think Rayden is the official spelling

MarxZero is on the right track.

'Raiden' is used in every arcade version of MK, and in MKDA and MKD. However, back in the early 90's another company owned the rights to that name and I think Midway woulda got in legal trouble had they used it in the home versions. So they changed it to 'Rayden', this continued on all the home versions from MK1 - MK4. Then I guess the company that had the rights to the name did not exist or did not care anymore in 2002, so "Raiden" (the official name) came to the home versions for the first time...

Raiden is the Japanese god of thunder and lightning, so that is the official spelling of the Mortal Kombat character's name. I think you guys are right; at the time, there were other characters named Raiden (Metal Gear comes to mind), and Midway probably thought that by using the name, they could get sued for copyright infringement. Of course, there's no way you can get sued over using the name of a god, so eventually, they made the official switch for the home versions to Raiden.

raiden from mgs2 was made after mk, so hideokojima didnt have the rights. i think its stupid if you "own" a name. certain names you shud b alowed 2 have e.g. tekken, combot is a unique name, but lee is not so you can only use lee. if raiden means thunder god, then they should b able to call him that.

They pronounce it different in MSG2 also, which confused me as well.

Wasn't the thunder deity in Japan called Raijin?

It might have had to do with the video game called Raiden. It was an overhead spaceship type game. I always thought it was a Midway game, but maybe not. It's older than MK, too.

There's a bunch of ways to spell it in Japanese, but Raiden is usually the most common. Since the 'j' and 'd' sounds in Japanese sound similar, it's easy to interchange them in different words.