But I came away with the overwhelming impression that the main job of Mass Effect 2 is to build the audience and anticipation for Mass Effect 3. (The franchise was always intended as a trilogy.)

I could almost see the portfolio theory at work at Electronic Arts headquarters. Next week, the company is scheduled to release Dante’s Inferno, a game based on the epic poem. Now that qualifies as a risk. And so I could almost hear the executives saying, “In that case, we need our other big game this quarter, Mass Effect 2, to play it safe.”

Of course, the result of BioWare’s playing it safe is still more interesting and impressive than most developers’ most inspired efforts. And the most interesting and impressive aspect of Mass Effect 2 is how intelligently the game melds the combat systems of a third-person action game with the storytelling and characterizations of a traditional role-playing game. The term “role-playing shooter” may have been coined by the creators of 2009’s Borderlands, but the phrase almost perfectly describes Mass Effect 2.

This is an important distinction and it signifies a new stage in BioWare’s development. BioWare has been known over the last 15 years as one of the world’s top makers of single-player role-playing games. Going back decades to Dungeons & Dragons, one of the cornerstone concepts of a role-playing game has been that players primarily build up their virtual characters through the meticulous accumulation and selection of equipment and skills. In a role-playing game, even those played online in real time, combat generally revolves around the shrewd, strategic use of gear and special abilities rather than on the human player’s spatial perception and eye-hand coordination  the province of a shooter or other sort of action game.

Hybrids are certainly possible. The original Mass Effect was a role-playing game that BioWare was ambitiously, almost rambunctiously, trying to cram into the form of an action game. With Mass Effect 2, by contrast, BioWare clearly decided to build the game as a shooter type first, leaving in only the lightest of customization options for each character  with far fewer skill options than in the first game  and fuse them with a combat system that can be played almost entirely as a real-time shooter. In terms of the combat dynamics, imagine Gears of War lite with some science-fiction magic powers.