If you have any content that mentions gold sales or real money transfers you will rank better for it then sites that do not. After all, the text on your web pages are a big part of Google's ranking algorithm. So if you mention it, you might rank well for it.
If you don't want to rank well for those terms don't use content that mentions those keywords. Also, don't have any content that would attract links using those keywords.
Having said all that, the odds of you ranking well for those terms are fairly slim. There probably are enough sites that are targeting those keywords that they'll naturally outrank you. Additionally, if you do come up for searches using those keywords, assuming you don't have an ODP listing or meta description tag, Google will use snippets of the page containing that text as it's description for your listing. That means users will see that your site is not for those things so they probably won't click through and visit your site anyway.