You don't really *need* to play 1, it is far inferior to 2 and 3 in terms of its game mechanics. Obviously I'd recommend looking at a bit of a story primer though - the overall plot gets recapped well enough at the beginning of 2 I think, but knowing who the characters are will help. It's actually one of the better series when it comes to strong characters, creating emotional attachment and all that good stuff, so it might be a bit weird going into 2 without context for any of them.