Well, any laptop you use to play games that do calculations constantly (especially real-time games with impressive non-pre-recorded moving 3D graphics) will use more power than they would if they were mostly just sitting there or doing something light such as browsing the web or using programs that are mostly waiting for the user. So in that sense, the time to use the battery power while playing games will be less. Also, because gaming laptops tend to be designed to have faster processors, those may tend to use more power, but whether they do or not when idle and how good their batteries are compared to other laptops, will vary by specific laptop. Sadly, there have been very few laptops designed to mainly maximize battery life as a major feature.