Contrary to popular gaming lore, the original System Shock was not a commercial failure and sold over 170,000 copies over time. But when it first released in 1994, gamers overlooked Looking Glass's groundbreaking game despite favorable reviews. Some erroneously discounted it as a Doom clone, even though it was actually the offspring of a line of games that preceded any of id Software's first-person shooters. Other players dismissed it as a derivative first-person role-playing game that arrived on retail shelves just after a parade of Wizardries and Might and Magics. In fact, System Shock was a game that defied pigeonhole classification because it borrowed elements and themes from a variety of genres. Yet it was precisely because of its creative design that it is now commonly, belatedly, regarded as one of the best computer games ever made. Irrational Games was given the difficult task of creating a worthy successor to the cult-classic original, and the new development company has responded by delivering a game that both retains the best attributes of its predecessor and provides a fresh experience in its own right.

Prompted by the near destruction of Earth by the self-aware and malevolent artificial intelligence SHODAN, Earth's previously ineffectual political governments formed the Unified National Nominate and imposed constraints on the power of megaconglomerates. But after inventing faster-than-light technology, the corporate creator of SHODAN, TriOptimum Corporation, convinced the UNN to engage in a cooperative expedition into unexplored space. Your character awakens in the midst of a crisis, as the ship that undertook the monumental journey has apparently become infested by some form of alien life. Suffering from that infamous RPG plot device, amnesia, your character finds that he has received illegal cybernetic implants that grant superhuman abilities - just the kind of endowments necessary to survive System Shock 2's chaotic circumstances.

Even though it's a sequel, System Shock 2 feels entirely original because too few RPGs have science fiction settings. This one offers a rich combination of psionic powers, contemporary and futuristic weaponry, and William Gibson-esque cybernetic implants and technical skills. The plot unravels as you listen to e-mail and message logs. While the convenient placement of dozens of logs throughout the otherwise realistic environments is a bit contrived, the messages are consistently engaging and gradually expand upon the fates of most of the game's key figures. Unfortunately, since the settings have generally been abandoned by friendlies, the logs all but replace direct interaction with nonplayer characters. You'll also experience a handful of scripted story sequences crafted using the game engine, as well as frequent and interesting ghostly reenactments of earlier events. Collectively these storytelling methods convey an intriguing plot and generate an eerie atmosphere that make System Shock 2 feel unique through to the end.

Like its predecessor, System Shock 2 is a first-person game that cannot be easily characterized otherwise. The role-playing elements are deeper than they were in the first game, as you're able to personalize your character's initial attributes and abilities and later update them in a variety of significant ways. The game looks and generally feels like a first-person shooter, but the RPG elements and detailed environments give the gameplay more depth. Unlike in a first-person shooter, you'll find it hard to be successful in System Shock 2 if you storm into every room, guns blazing. Ammunition is scarce throughout the game, forcing you to warily advance through dark hallways, leaning around corners to look for additional resources and opportunities to dispatch unwary foes. Even solitary enemies can be dangerous, and carelessly trekking into an unexplored room will often alert a security camera, which summons a legion of enemies to finish you off. Consequently, travelling through the creepy surroundings often slows to a crawl, even while backtracking since enemies randomly regenerate.

System Shock 2's engine is well equipped for such stealthy maneuvering, as it's essentially an enhanced version of the Dark Engine created by Looking Glass for Thief, combined with some of the better interface features and controls of the original System Shock. The engine's 3D-accelerated graphics are capable of producing a variety of plausible futuristic environments, and its ambient fog and lighting effects look particularly good. However, the engine seems less capable of depicting characters, as humanoid figures look like a fusion of rudimentary polygonal shapes masked by a decent texture map. But since there are some plot justifications for the irregularly shaped beings, and most of the game's settings are extremely dark, the relatively simplistic character models work fine, even if they're not as detailed as those action gamers now expect.The game's dynamic music is appropriately fast-paced or atmospheric depending on the circumstances, but its crisp sound effects deserve particular praise. Environmental audio is a supported feature that's used to great effect. Straining in the darkness to gain foresight into the challenges ahead becomes an essential tactic, whether it be to detect the distant whirring noise of a security camera, the haunting ramblings of a mutant hybrid, or the banter of a haywire protocol droid. It's all great stuff, and it contributes significantly to the tense mood rapibly established in the game.

One of the best aspects of Thief's engine was that it accounted for how noisy and how visible your character was and ensured enemies responded accordingly. Fortunately, all this is intact in System Shock 2. Don't expect to be able to casually open the door to one room, deal with its inhabitants, and then open the next door and repeat the process. If any creatures are within earshot of combat, they'll rush to join the fun, making it important to choose your battles carefully. Enemy AI is very good generally, as even basic grunts charge after you instead of haplessly lumbering in pursuit, while certain deadlier opponents will stick to shadows from where they'll launch their rapid-fire attacks.

Fortunately, System Shock 2's interface is well designed and even fits well with the game's plot. You can maintain a view of the gaming world while searching through your inventory and use hotkeys to quickly access weapons, use items, or listen to log messages. To help you navigate you can superimpose semitransparent compass directions over your viewing window, pull up an automap, or maintain a miniature version of the map onscreen. Since your character is supposed to be grafted with a variety of cybernetic implants, there's actually a reasonable justification for your ability to access information such as this. The interface is not only effective, but it actually contributes to the game's ambiance instead of detracting from it.

Your character is initially trained in one of three military branches - marines, navy, or OSI - each emphasizing a different proficiency: weapons, technical skills, or psionic powers. But the professions don't add as much depth as you might expect, since during the course of the game you can choose to develop any skills or attributes regardless of your initial choice of profession. The professions are badly unbalanced as well, especially at the beginning of the game when the modules used to upgrade your character are extremely rare. It's very difficult to survive without picking up at least a smattering of basic weapon and technical skills, and since navy characters start the game with those abilities, they have a huge advantage. Meanwhile, marines are essentially navy characters stripped of those vital technical skills, while OSI characters lack both weapons and technical skills and are extremely fragile initially for lack of items that restore their psionic energy. During the course of the game you can develop truly different characters that are capable of successfully completing the game in their own right, but the initial selection of profession isn't relevant or even enjoyable in the manner in which it was intended.

Finally, despite System Shock 2's novel setting and its RPG elements, its gameplay doesn't really evolve significantly beyond that offered by recent first-person shooters. You'll spend much of your time strafing at enemies around corners, opening crates, and even hunting for keys. But the realistic environments, intriguing plot, and consistently uneasy atmosphere make System Shock 2 constantly effective. It is a hybrid game that effectively blends elements from a variety of genres into a thoroughly enjoyable and accessible package.