Operation Flashpoint: Resistance is an expansion pack to Operation Flashpoint: Cold War Crisis. It was developed by Bohemia Interactive, authors of the original game, and published by Codemasters. It is second expansion of Operation Flashpoint while the first one is Operation Flashpoint: Red Hammer, which was developed by Codemasters. Resistance was later re-released as part of ArmA: Cold War Assault.Resistance features updated graphics, sounds, and multiplayer mechanics. Unlike Cold War Crisis which is more focused on infantry combat, Resistance focuses heavily on guerrilla warfare and its tactics such as raids, ambushes, and escape and evasion. The player can also control AI guerrilla units giving it an RTS feel. There are also many weapons and vehicles ranging from Tokarev pistols and AK-47 assault rifles to LAW rocket launchers and Hind attack helicopters. Multiplayer also exists which can be PvP or Co-op. A mission editor is also included where players can create their own multiplayer maps. In the beginning of the game, it features the invasion in a civilian's point of view. In certain missions, the player can call for guerrilla reinforcements but only in missions where it is part of the objective.
There also is new campaign and new island Nogova which lies on 144 Square kilometers. Towns and villages are named mostly after real places in the Czech Republic. The plot is inspired by the Warsaw Pact invasion of Czechoslovakia.
The storyline takes place three years before the events of Operation Flashpoint: Cold War Crisis. The player takes on the role of an ex-special operations soldier, Victor Troska, who has returned to his homeland of Nogova after years in exile serving with British Special Forces. During the first introductory mission to the campaign, the island is invaded by the Soviet Union after some members of the socialist party betray the country and invite Soviet forces to overthrow the government. Troska is approached by Nogovans who are resisting the Soviet occupation and asked to join them. Initially, Troska refuses to have any part in the fighting and rebukes them because he wants to put the combat behind and also believes that any resistance will take many of the inexperienced soldiers' lives. Later, a wounded guerrilla fighter being pursued by Soviet soldiers takes refuge in Troska's shed. When Soviet soldiers, led by Colonel Guba, arrive, Troska is forced to make a decision: betraying the partisan, trying to negotiate with the Soviets or fighting off the Soviet soldiers and joining the resistance.
- The first choice makes Viktor to join the Soviets who give him a task to locate the main resistance base and reveal its position to Soviets. After finding the base, Victor is once again forced to decide whether he will betray the partisans or lead the Soviets to the false location to join the resistance anyway. If he chooses to betray them, the Soviets win and Victor is executed with the other partisans as a traitor who cannot be trusted because he betrayed his close friends.
- The second choice only makes the Soviets more angry and the negotiation is unsuccessful.
- The last choice forces Victor to grab the gun, kill the Soviets holding him and his friends at gunpoint, and escape to join the resistance.
When Victor joins the resistance, he is immediately forced to take command and fight the Soviets who attack their base and kill the resistance commander. Then he leads his units to assault some Soviet bases and convoys to collect some weapons, ammunition, and tanks as the resistance forces have only a limited supply of weapons. Besides the fighting, this becomes a very important objective through all throughout the campaign. After some initial successful actions more people begin to join the resistance, making it stronger. Later, the resistance receives some weapons and supplies from the Americans who also send James Gastovski and his team in to assist the resistance. Victor is also helped by "Tasmanian Devil", an informant of unknown identity who passes critical information to him via radio (he is later discovered by the Soviets and killed). The successful actions drive the Soviets back until they are pushed to the airfield where Guba holds his tactical bombers to be used to obliterate Nogova after the Soviet retreat. Victor manages to destroy the bombers but the Soviets encircle him and is missing after that, presumably dead. The American forces sent by Colonel Blake wipe out the remaining Soviet forces but Guba escapes before the final defeat.
- Victor Troska - He is the main protagonist of the game and the leader of Nogovan resistance. He is a former member of the special forces. He is tired of wars and has left the army. He lives in Nogova where he is employed as a judge. After the Soviet invasion of Nogova, he reluctantly joins the partisans and becomes their leader.
- Aleksei Vasilyevich Guba - He is the main antagonist in the game and the commander of Soviet forces in Nogova. He is a colonel of the Soviet Armed Forces.
- James Gastovski - A member of Special Forces (United States Army). He is an old friend of Victor. They served together but James didn't leave the army. He is sent to Nogova as part of special operation and chooses to retire after the Soviets on Nogova are defeated.
- Geronimo - He is the second highest partisan leader. He participated in founding the resistance.
- Tasmanian Devil - He is a person who informs partisans about Soviet plans. His identity remains unknown for the whole game. He is later located by Soviets and killed.
- Stoyan Yakotich - Resistance member who serves under Troska. He is killed by another patisan.
- Gabriel - The original leader of Nogovan resistance and its founder. He is killed during Soviet attack causing Victor Troska to replace him.
- Liz - Victor's love interest. She is a widow. Her husband was friend of Troska. She is taken as a hostage by Soviet forces and killed in a firefight between resistance and Soviet forces.
Resistance was released to generally positive reviews. It was praised for its story and the whole idea of guerrilla warfare as well as its for missions and technical improvements but it was also criticised by some reviews. Technical improvements are according to some critics unnoticeable and missions were criticised for less variety than the original game.