It is an rts game. rts stands for real time strategy. there are 3 races, the terran (humans), zerg (swarm), and protoss (psionic beings). they are basically all fighting eachother for unknown reasons (there are reasons just dont want to spoil it). if you want to play the game for the lore only i recommend getting starcraft 1 remastered edition which is $10, but you can figure out the lore if you just start from starcraft 2. starcraft 2 is the newer version and the terran campain, 3 co-op commanders, and all the online features (like the arcade, tournaments,and matchs) are free. if you want the zerg, protoss, and nova ops pack you will have to pay. (i bought it and it was a good investment).