As I already laid out in my post about „What is Mouse DPI“ this abbreviation stands for „dots per inch“ – the resolution your mouse sensor can track per inch. Some mice can track 400 single dots per inch (a 400dpi mouse), while others can track 12,000 dots per inch (like the Logitech G502 for example). As a rule of thumb: the higher the dpi value of your mouse is, the faster you can use your mouse without any flaws or tracking errors. This is especially important for fps gamers, so that you can do these fancy quick AWP flicks in CS:GO with the highest possible precision.
But: do we really need maximum dpi values of over 9,000 (epic meme m8) to have the best aiming in game? The clear answer here is No! Although some mice manufacturers might tell you otherwise (and a lot of them do), everything above 4,000 dpi is useless! If someone should tell you that a specific 10,000 dpi mouse is better than a 8,000 dpi mouse because of that, he’s bullshitting you. Try playing an ego shooter with such extreme dpi values – you’ll do three-sixties 24/7 because your mouse is way too sensitive.
So – how much dpi does a good gaming mouse need?
For most gamers 1,000 to 2,000 dpi is enough. You will not use anything above that anyway, so why care about it? If you use a very high sensitivity you can go for 4,000 dpi just to be sure – but you really don’t have to. Everything above that is pure marketing and not needed for any gamer – so don’t let five-figure dpi values fool you into buying a certain mouse when you actually don’t need it.