In the American campaign, the player controls Private Nichols, a replacement for the 29th Infantry Division. After arriving in a staging area outside Saint-Lô, he is assigned to his new squad consisting of veterans Corporal Mike Dixon, Private Leroy Huxley (voiced by Benjamin Diskin), and the squad’s CO, Sergeant Frank McCullin. Shortly after Nichols’ arrival, the squad participates in the final offensive in the capture of Saint-Lô. Upon arriving at the outskirts of the town, McCullin enlists radio operator Private First Class Salvatore Guzzo, who had become separated from his unit, to assist the squad in the attack, despite the latter’s objections. During the street to street fighting, the squad takes shelter from a German artillery barrage, during which Guzzo demands that the squad should fall back. As the shelling intensifies, Guzzo loses patience and tries to leave but is stopped by McCullin, who threatens to shoot him for desertion. After the squad fights off a German counterattack, Saint-Lô is declared secure. Shortly after the battle, the squad is folded in with the 90th Infantry Division as reinforcements to help secure Saint-Germain-sur-Sèves.
Later, the squad takes part in the assault on Mayenne in order to capture its heavily fortified bridge. After the squad fights through a German garrison, Huxley is tasked with disarming several German bombs rigged to the bridge, but is wounded before he can begin. McCullin, a former combat engineer, takes Huxley’s place to disarm the bombs. McCullin is mortally wounded by a German mortar round but manages to disarm the final bomb. Dixon is promoted to Sergeant and assumes command of the squad.
Shortly after, the squad is sent to clear out Forêt d’Écouves in order to aid the 2nd Battalion’s advance and to locate a company of combat engineers that had gone missing. They eventually locate a surviving engineer, who explains that their convoy was ambushed and supply depots overrun. Nichols and the squad are able to recapture the supply depot and destroy a German roadblock, effectively clearing the remaining Germans out of the forest. The squad is then sent to aid in the liberation of a vital crossroads at Le Bourg St. Leonard, effectively trapping the remaining German forces between the US forces to the south and the British, Canadian, and Polish forces to the north, all but closing the Falaise Pocket, but are displeased when they are then ordered to defend the town of Chambois, the last escape route for the Germans trapped in the Pocket.
Shortly after occupying the town, Nichols’ squad and the other defending American units come under attack from a massive force of retreating Germans. After much fighting, Guzzo attempts to call for air support to destroy enemy positions, but his radio is destroyed by enemy fire. Resorting to using signal flares and braving heavy German fire, Guzzo is able to successfully mark the targets, but is wounded. Nichols and Dixon are able to rescue him just as air support attacks the enemy targets, but Dixon is shot and killed just as they reach Allied lines. Enraged by Dixon’s death, Guzzo takes command of the squad and leads them to aid the remaining American defenders to retake and defend the town just as air support and American reinforcements arrive, forcing the remaining German forces to surrender. Two days later, the squad members receive promotions, with Guzzo officially promoted to Sergeant and Nichols and Huxley being promoted to Corporal, and begin their march to liberate Paris.
In the British campaign, the player controls Sergeant James Doyle, a member of the Special Air Service (SAS), who alongside squad mates Corporal Duncan Keith, Wilkins, and Major Gerald Ingram, are parachuted into France in order to assist the Maquis Resistance in several operations to reduce the fighting capability of the German forces fighting in Normandy. Shortly before reaching their drop point near Toucy, France, the group’s Handley Page Halifax is shot down, with Doyle and Wilkins being separated from the rest of their squad. Wilkins is executed shortly after landing and Doyle is rescued by Pierre LaRoche, the Maquis leader, before regrouping with Keith, Ingram, and resistance member Isabelle DuFontaine. After retrieving their two heavily armed jeeps, Doyle and the group assault a manor house that is serving as a German HQ in order to free a captured Maquis member, a man known only as Marcel. After escaping the area and regrouping, it is revealed that Marcel managed to steal the plans of a German held fuel plant before he was captured. Keith, who already holds great disdain for the resistance fighters and the French in general, immediately begins to butt heads with LaRoche, citing his lack of confidence in the Maquis and distrust of Marcel in particular.
Using the captured plans, the SAS and Maquis launch a raid on the plant in order to destroy its fuel storage tanks and production facilities. The raid is a success and destroys the facility; Doyle, Keith, and Marcel manage to escape the area, but the vehicle carrying Ingram is hit by German fire and Ingram is seemingly killed. Regrouping with LaRoche and DuFontaine sometime later, Keith berates LaRoche, who had left early during the raid, calling the Maquis leader a coward and accusing Marcel of being a German collaborator.
Following the destruction of the fuel plant, the group receives information that Ingram is still alive and being held captive in a nearby village. Despite LaRoche’s objections, Doyle and Keith lead a rescue mission and manage to rescue Ingram and several captured Maquis fighters from interrogation and execution, before fending off a German counterattack, during which Isabelle is killed when a satchel charge she is planting on an armored car detonates prematurely. Marcel, visibly saddened by her death, is comforted by Keith, who has finally learned to respect the Maquis and their bravery.
In the Canadian campaign the player controls Private Cole of the 4th Canadian (Armoured) Division, led by World War I veteran Lieutenant Jean-Guy Robichaud. Robichaud commands a platoon in the Argyll and Sutherland Highlanders of Canada, aided by Sergeant Jonathan Callard, squad member Private Kyle Peterson, and the squad’s radio operator, Private Leslie Baron, who is continuously harassed by Robichaud for his lack of experience and habit of being seemingly absent during fighting. After their convoy is ambushed during a nighttime attack on a German-held industrial complex near Tilly-la-Campagne, the platoon proceeds to attack a German artillery battery on a nearby ridge, before moving on to capture the industrial complex and holding off an enemy counter-attack, destroying several German tanks in the process. The platoon later proceeds to clear a forested area near the Laison River of several anti-tank positions and a motor pool in order to clear the way for Allied convoys to move through the area. While advancing alongside other Canadian units to relieve Polish forces defending Hill 262, Baron is volunteered by Robichaud to be transferred to the Polish 1st Armored Division after the Polish unit’s radio operator is killed. Fed up with Robichaud’s abuse, Baron initially objects, stating that he is not a coward as Robichaud seems to believe, before storming off, much to Callard’s concern.
Cole’s squad is then tasked to lead a rescue mission to free a captured Canadian tank crew in St. Lambert-sur-Dives, and with their help eventually capture the whole town. Shortly after freeing the tank crew, the squad comes under attack from a King Tiger tank. While attempting to flank the tank, the squad discovers a German munition stockpile in a cellar directly beneath the tank, and plant explosives to take out both the munitions and the tank. When the charges fail to detonate, Callard returns to the cellar and detonates the charges manually, destroying the King Tiger and dying in the process, with Cole and Robichaud being knocked out by the blast. Waking up sometime later, Cole learns from Robichaud that Callard is being recommended for the Victoria Cross and that he is being promoted to Corporal. Shortly afterwards the unit moves out to join Canadian reinforcements advancing to aid the Poles struggling to defend Hill 262.
The Polish campaign revolves around Corporal “Bohater” Wojciech, a Sherman Firefly tank driver in the Polish 1st Armored Division and his crew members, including Major Stan “Papa Jack” Jachowicz, Corporal Joakim “Lucky Rudd” Rudinski, Sergeant Łukasz “Bang Boom” Kowalski, and Private Marek “Beksa” Ulan. While aiding the Canadian and British forces in the area, Jachowicz’s crew participates in a sweep across the French countryside, engaging German armored units while advancing to capture and occupy Hill 262, known as “The Mace” by the Polish. Bohater and his crew eventually track down and destroy an infamous Tiger II tank ace known as Richter “The Black Barron” (a reference to real life Tiger ace Michael Wittmann).
Bohater and his crew then join in the defense of Hill 262 and endure a heavy assault by the remnants of the German 7th Army in their desperate attempt to escape the Falaise Pocket. Bohater’s tank is destroyed shortly after the attack begins, forcing the crew to fight on foot alongside the Polish infantry. With their position overrun, Bohater and his crew continue to fight the Germans as they retreat towards the summit of Hill 262. They are eventually joined by Baron, who along with Bohater provides artillery support in order to destroy several German tanks. As the crew continues to climb the hill, Baron refuses to retreat any further, having been deeply affected by Lieutenant Robichaud’s constant teasing, and demands to stay and fight instead. However, he is killed by German fire while arguing with Ulan, who salvages the radio in order to continue providing artillery support. Upon reaching the top of the hill, the crew spots what they believe to be the Canadian reinforcements, only to realize it is instead a massive German counterattack, during which Rudinski is killed. After much fighting, the Royal Canadian Air Force appears and repels the German forces as the Canadian reinforcements arrive at last, leaving Hill 262 firmly in Allied hands. Major Jachowicz meets with Lieutenant Robichaud after the battle and expresses his desire to collect the bodies of his men and return them to Poland, as well as stating his belief that the Germans will soon be defeated. However, Robichaud is quick to remind him that the Germans still have an escape route through Chambois should the Americans fail to stop them.