Gaming mice are generally more sensitive then normal mice, which is useful for people playing first or third-person shooters, where every millisecond counts. However, unless you are playing at professional level, it's generally not required, and doesn't make an excessive amount of difference either way. Gaming mice also tend to have extra buttons to bind to useful functions, so that may come in useful for you if you don't like the current binding system for your games. If you do plan on buying a gaming mouse (I'm assuming you're not playing at a professional level, i.e. serious clans, playing in tournaments for cash prices, etc.) then look out for a cheap one, rather then spending a lot of money on a more expensive model. I happen to own both a Logitech G5 and a Saitek Cyborg, but I still prefer to play with my £5 ($10) Trust Predator 90% of the time.