All laptop now should be able to play DOTA without any prob with 1G ram and above. My friend got one laptop using celeron and 1.2G ram is able to play DOTA but a bit lag while all heroes fighting each other in one screen. And, if u are using vista, 1G is not good enough. At least 2G ram for vista will give you very good performance. Lastly, if u rich enough, go get a laptop with graphic such as 8600gt or better^^
