Arma II is a first- and third-person tactical shooter that simulates a military operation in the midst of a growing civil war in the fictitious European country of Chernarus. The sequel to Armed Assault and the spiritual heir to Operation Flashpoint, Arma II sets a new standard for realistic military simulation games. While Bohemia Interactive's games have always been detailed and ambitious, its latest has surpassed its predecessors by adding meaningful interaction with non-player characters (other than shooting them), increasing the number of moral and strategic choices you will face throughout the campaign, and achieving unprecedented levels of detail, openness, beauty, and believability in the setting. Despite an infuriatingly buggy single-player campaign and some artificial intelligence driving issues, Arma II is a triumph. From its fascinating, sophisticated, and unscripted battles to the immersive detail of the gameworld, Arma II delivers a wholly unique and uncommonly replayable gaming experience.

Can you see the insurgent in this photo? Combat in Arma II often takes place at a range of 100 meters or more.

Arma II’s setting is visually striking, amazingly detailed, and brimming with life. Modeled after regions of the Czech Republic, the landscape is so authentic that you could orienteer by watching the stars move across the sky. The terrain includes picturesque forests, mountains, beaches, and pastures, plus one large urban area and several smaller towns, and in many missions, you'll have free rein to traverse vast tracts of the 86-square-mile gameworld. Alongside the Chernarussian people, wild animals and livestock go about their respective lives. However, the animal AI is disappointingly indifferent to the war. Another element of the environment that can interrupt the immersion is the scarce number of civilians you'll encounter per town, along with how few buildings you can enter. On the whole, however, finding a well-worn trail in the forest or commandeering a farmer's tractor for the occasional joyride makes the world feel lived in and real.

Like the geography, the story is refreshingly complex and believable. In the former Soviet Republic of Chernarus, five factions vie for power, including the US Marines, your faction for the single-player campaign; the Chernarussian military, which is allied with the US; the Red Star Movement, a group of Communist separatists from the ethnically Russian areas of Chernarus; NAPA, an independent group of nationalist partisans fighting the Communists; and the armed forces of the Russian Federation. Although your mission is to help the legitimate government in its campaign to crush the Communist insurgency, it's not always clear which factions are in the right; they're all guilty of corruption and atrocities.

In contrast to many first-person shooter games, the war doesn't stop and start at your convenience. You'll find corpses, stumble upon unscripted battles, and encounter friendly troops on patrol, creating the impression that the fighting will continue with or without you. At the same time, your actions can have a profound influence on the story as the campaign unfolds. For example, at one point, you can become instrumental in forming an alliance between NAPA and the Chernarussian government, and at another, you can follow up on evidence of Communist war crimes to win the hearts and minds of the natives. Civilians can often provide intelligence about nearby enemy forces, rebel leaders, and their hideouts, but don't get too attached to your new friends, because enemy partisans don't take kindly to collaborators. In the campaign, each path you take develops fluidly into new missions, which typically begin with a simple objective, like scouting an area, and lead to additional optional objectives, based on your choices. Will you risk your squad and engage your target on foot, or will you endanger nearby civilians by calling in a missile strike? The ramifications of your actions will bear both on your immediate situation and on how the game unfolds several missions down the line. Other missions will send you deep into enemy territory to scout for insurgent bases, capture rebel leaders, rendezvous with partisans, and take part in a wide variety of other realistic military operations.

Helicopters are the best way to travel across Chernarus. Be careful with the minigun, because the brass frowns on unnecessary civilian casualties.

You start off as a grunt under the command of a squad leader, and you'll play the first third of the game as a straightforward infantry simulation. To survive, you must learn the importance of scanning the horizon before you move, flanking enemies, aiming with your weapon sights, and keeping a low profile. Combat is deadly serious in Arma II; a single gunshot to a critical area will kill you outright, while nonfatal wounds will leave you incapacitated and bleeding out until you receive medical attention. As a result, combat reaches a level of intensity rarely accomplished in action games, and every success is immensely gratifying, whether you are running for cover with bullets whizzing past your head, killing an enemy soldier from 200 meters away, or destroying your first tank with an RPG. You'll find that bullets are typically exchanged at a distance of 100 meters or more, at the far edge of visual contact. Aiming at this range is a ballistics puzzle that rewards intelligence over reflexes, and "spray and pray" tactics will only win you a trip home in an unvarnished pine box. Even though combat is extremely difficult, it's always fair. The average AI enemy, while a good shot, isn't inhumanly good and can be tricked or flanked. Unfortunately, the AI characters on all sides are atrocious drivers and have a knack for causing traffic jams, capsizing vehicles, and flattening allies. AI helicopter pilots, on the other hand, rarely crash, unless you ask them to land in the middle of a dense forest. However, they're an impatient bunch and tend to take off before your whole squad can get in the chopper.