Coalition of Ordered Government (C.O.G.)
The main character, he is a soldier thrown in prison 14 years prior to the start of the game. Before "Emergence Day" (the day that the Locust Hoarde invaded), there was a huge war going on between all of the nations in the world. When oil supplies were running low, an alternate energy source, called "Immulsion," was discovered. It turned out that Immulsion was not only more productive than oil, but it was environmentally friendly. Some nations had bountiful amounts of Immulsion, some had none. When the less lucky nations attacked the ones with all the extra energy, the Pedulum Wars had begun. Sera (the planet Gears Of War takes place on), was torn apart in war, and no one saw the Locust invasion coming. When the Locust attacked, Marcus was instructed to protect civilians and to fight the Hoarde, but instead he went to save his father and was charged with treason.
Son of famed military scientist Adam Fenix, Marcus established a reputation as a brilliant soldier during the Pendulum Wars, earning field promotions and decorations. He was on a fast track to an outstanding military career, until the war with the Locust Horde began. One long decade after Emergence Day, the Horde Army breached Jacinto Plateau's defenses and Marcus defied orders so he could save his father. He was too late, and in addition to losing his father, Marcus was charged with dereliction of duty and was sentenced to 40 years in Jacinto Maximum Security Penitentiary. It's later shown that Marcus's father was mapping the underground tunnels of the Locust Horde (a detail integral to the plot of Gears of War), although it's never revealed whether Marcus was aware of how important his father's research was when he attempted to save him, or whether he specifically knew it related to the Locust Horde. Four years into his sentence, the Horde overtook the Jacinto Penitentiary, but Marcus was rescued by his best friend, Dominic Santiago, so that he could join the fight against the Locust Horde Army. Marcus Fenix is 35 years old at the start of Gears of War. Marcus Fenix's design varied at several points in the development of Gears of War. It appears that at one time in development, he had a different appearance. Early game art and renders show that he was originally bald and did not have any facial hair. Popular voice actor Steven Jay Blum originally voiced Marcus Fenix in an early build of the game, but was later replaced by John DiMaggio. DiMaggio is well known as the voice of the character Bender from the TV series Futurama. Marcus' final character model carries an Epic Games logo on his bandanna.
Dom is Marcus' best friend and comrade, this is exaggerated by the fact that in co-op play the second player is Dom. When Marcus was on trial he stood by testifying that Marcus was not a coward and saving him from the death penalty. His wife Maria disappeared at the onset of the war so he is fighting the locust for her sake. He is also owed some kind of debt by Franklin, a Stranded, that is paid back during the campaign.
Dominic Santiago is a vocal, colorful and yet practical soldier. He's loyal to a fault, especially with his friends, and has no patience for those that think of themselves first. Dominic has always believed in his country and his leaders, but his faith has been slipping in the face of this endless war. Dom lost his wife in the Emergence Day cataclysm. For him, the fight against the Horde is deeply personal.
By testifying in Marcus' defense, Dom prevented an execution, but was forced to accept the heavy judgment the military tribunal handed down to his childhood friend. Never forgetting, Dom seized his first opportunity to save Marcus' life, and convinced Lieutenant Minh Young Kim to enlist Marcus into his squad. In the beginning of Gears of War, Dominic Santiago frees Marcus Fenix from the Jacinto Maximum Security Penitentiary under orders from Lieutenant Mihn Young Kim. The two characters begin the campaign trying to escape the prison, which is now overrun with Locust Horde.
Augustus Cole, aka "The Cole Train", is a former professional Thrashball player for the Cougars. He craves action and prefers the most direct path to his next fight. What he lacks in finesse, he makes up for in raw energy. Along with his child-like enthusiasm and charm, Cole is confident in his own abilities to overcome anything. He has yet to be proven wrong.
Cole, aka "The Cole Train", is an adrenaline junkie and former professional thrashball player for the Cougars. He craves action, and prefers to take the most direct path to the Locust Horde in any situation. What he lacks in finesse, he makes up for in raw energy. Along with his child-like enthusiasm and charm, Cole is supremely confident in his own abilities to overcome anything, regardless of the odds—and he hasn't been proven wrong yet. Cole and Damon Baird have served together for years, and he treats Baird as he would an older brother with a younger brother's license to torment. Augustus "Cole Train" Cole is voiced by Lester "The Mighty Rasta" Speight. While relatively unknown, Lester Speight is legendary for his acting as the man who plays as "Terrible" Terry Tate, the "Pain Train", in the Office Linebacker commercials made for Reebok. The game's cinematic ending also leads into a credits sequence featuring a hip-hop remix of the various "Cole Train" voice overs encountered throughout the game. He is listed at being 6'2 and close to 280 pounds (110 Kg.)
Baird is the cynical and often argumentative tech expert of the squad. He holds a grudge against Marcus for getting promoted to team leader instead of him. He's revealed to be the tech expert when he is assigned to repair an APC in act 4.
Despite being a reluctant and cynical soldier, Baird excels at the military life. Baird is perfectly capable of being a successful officer, but has never been promoted due to his poor attitude, short temper and his unwillingness to take on any responsibility. Baird's greatest strength is his intelligence. He not only fights the Locust, but he studies and observes them as well. He's the closest the COG have to an expert, and when Baird tells his comrades to be quiet and listen, they know it is in their best interest to do exactly that. Baird's only motivation is self preservation. He's willing to do whatever it takes to get through the war alive -- even march along side a troublemaker like Fenix. Baird's expertise also includes a specialization in mechanical and repair-related skills. In Act 4 of Gears of War, when Delta Squad finds an APC offline, Baird is able to fix it given time and the use of pure ingenuity.
Lieutenant Minh Young Kim
Lt. Kim is a "by the book" soldier, following every single rule and code of conduct to all things COG, making him an excellent Lieutenant. When the squad reaches the ruined courtroom(where Marcus was condemned to prison), Marcus makes a crack about the court, labeling it for it's "lies". Kim then barks at him for his disrespect. At the end of Act 1, a King Raven helicopter arriving to evacuate Alpha and Delta Squad is taken down by Nemacyst spores, and Kim is separated from the rest of the Gears in the ensuing firefight. Amidst all the chaos, Kim orders a retreat and distracts the incoming Locust Horde, unaware of General RAAM approaching him from behind. Too late to defend himself, RAAM impales Kim on a jagged sword.
Lieutenant Kim is a proud, dedicated and ambitious soldier, a by-the-books believer in all things COG. To Kim, the Coalition of Organized Governments is humanity's only hope for survival and feels that it is an honor and privilege to serve as a Gear. Kim moved quickly through the ranks, but after a run of bad luck he was left leading the misfits of Delta Squad. Feeling undervalued and overlooked, Kim has something to prove. Only the strength of Dom's faith -- and the scarcity of experienced soldiers -- convinced Kim to consider bringing former prisoner Marcus Fenix into his squad. Near the end of Act 1 of Gears of War, a King Raven helicopter comes to evacuate Delta Squad and Alpha Squad. However, Nemacyst spores bring the King Raven down and emergence holes spring up everywhere. Amidst all the chaos, Kim is yelling out orders while General RAAM emerges with all manner of drones. Kim is skewered by General RAAM's blade in a cinematic sequence.
"Voted most likely to get shot" in the COG Academy (according to his multiplayer character description), Pvt. Carmine is a member of Delta Squad at the beginning of the game, along with Lt. Kim, Marcus Fenix and Dominic Santiago. In battle Carmine will often rush out into the open, and has a gung-ho attitude. In Act 1, while standing up to complain about his Lancer rifle jamming, he is shot in the head by a Locust sniper. His face is never revealed and his character is underdeveloped resulting in him being a kind of throw-away character that is quickly forgotten once he dies in the story.
However in online gameplay Carmine is undoubtedly one of the top played COG players. This popularity is making Carmine's brother, Benjamin, appear in Gears of war 2.
Lieutenant Anya Stroud
Anya is the only female character in Gears of War and only briefly appears in person. She is the Gears' source of information constantly informing them of incoming enemies and satellite activity. Without Anya the Gears would undoubtedly have died.
Colonel Victor Hoffman
Like Anya Stroud, Hoffman is rarely seen in Gears of War, often sending orders via radio. Hoffman first appears in the third cinematic, telling Marcus he is a traitor and doesn't deserve to wear the uniform, and the final cinematic aboard the King Raven with Dom, Cole and Baird after defeating General RAAM. Initial interactions between Marcus and Hoffman are extremely confrontational, although Hoffman comes to have a grudging respect for Marcus by the end of the game; in the final cutscene, as Marcus leaps to a helicopter from a train which is plummeting into a canyon below, Hoffman reaches his hand out to help Marcus onto the helicopter and gives a small, yet noticeable smile of approval. In the final cutscene of the game, he is heard giving a speech proclaiming victory over the Locust Horde and praising the Gears.
A Jack of all Trades robot, Jack for short. It has limited A.I., does not talk, and responds only to simple commands. It is always alongside Delta Squad, hovering about with a cloaking device that makes the robot unseen until it decloaks to make itself useful.
Jack is used for cutting doors, communications, first aid and minor field surgery, as well as other delicate operations both during and outside of combat. Often the Gears will have to defend Jack while it cuts open doors. In Act 4 of Gears of War, Jack is also used to download and store Adam Fenix's research data, which contained amazingly detailed maps of the Locust underground systems.