Rainbow Six 3 is a tactical shooter game DEVELOPED by UBI. The game is a first person shooter based on Tom Clancy's best selling novel by the same name. The game has two expansion packs, Athena Sword and Iron Wrath. The plot of Ravenshield is fully explained by Wikipedia (Tom Clancy's Rainbow Six 3). Basically it is all about an elite anti-terrorist group called Rainbow Six, a team bent on foiling the Neo-Facist terrorists doing damages on South American oil interests and European financial institutions.
This game is an absolute classic. The fact that it still has an online community after nearly ten years is a testament to the quality of gameplay. Whether you enjoy single-player missions, online cooperative terrorist hunt, or frantic deathmatch games, Raven Shield delivers. It's not the mindless on-rails gameplay of the Call of Duty series or the R6 Vegas games, where you are always forced down one narrow route; in Raven Shield your choices matter and strategy is of ultimate importance. Other notable features of the game include an absolutely massive weapon selection and a huge selection of community-made maps. There are also great mods available, which can increase your weapon choices, let you fight zombies, or even purchase guns!
I consider Rainbow Six 3 as the last of the original RS generation game. After RS3 it all went downhill and the original concept and perhaps purpose of the titular Rainbow unit was lost. Somewhere between the idea of making them more of a mountain assault shock troops and a desire for getting to the wider audience. Rainbow Six 3 also have one thing: the plausible feeling that you are participating in scenarios which are based upon real possibilities some which are unique like hostage rescue ops in Congo posing as Belgian paratrooper commandos. Overall, it rocks.