There are two difficulty levels for Outbreak: Normal and Pandemic. While both play the same way, Pandemic features stronger enemies and friendly fire.
Outbreak takes place in Truth or Consequences, New Mexico. There are three different missions available: Blowing up a nursery for the infection, rescuing a doctor who has information of Patient Zero and rooting out the source of the infection.
Scattered around maps are crates for ammunition, gadgets, reinforcements and health. Only ammunition kits are unlimited. Using a Supplies kit replenishes all consumables and Health.
There are a number of fundamental gameplay tweaks in Outbreak to accommodate the drastically different setting. Among them, the speed of reloading has been increased slightly, alongside a faster time to Aim Down Sights. Barricades and Reinforcements for this game mode are unique in that they are yellow, smaller, and deploy significantly faster.
Heavy Armored Operators move at a faster pace than usual. Some of the Operators' gadgets have been tweaked, Ash's Breaching Rounds, for instance, detonate immediately upon impact and deals more damage, behaving like a more traditional grenade launcher.
Operators also have access to different secondary gadgets, including those not typically available to their "side". The only gadgets available are three Frag Grenades, two Stun Grenades, two Smoke Grenades, two Claymores, two Nitro Cells and three Impact Grenades.
- Smoke comes equipped with Smoke Grenades instead of his Barbed Wire, alongside his usual Impact Grenades.
- Ash comes equipped with Nitro Cells instead of her Breach Charges, alongside her usual Stun Grenades.
- Doc comes equipped with Smoke Grenades and Impact Grenades instead of his usual gadgets.
- Kapkan comes equipped with Claymores instead of his Impact Grenades, alongside his usual Nitro Cells.
- Tachanka comes equipped with Stun Grenades and Claymores instead of his usual gadgets.
- Ying comes equipped with Frag Grenades instead of her Breach Charges, alongside her usual Smoke Grenades.
- Finka comes equipped with Frag Grenades instead of her Breach Charges, alongside her usual Stun Grenades.
In Truth or Consequences, New Mexico, a local, Boyd Brooks, sights a falling meteorite and follows it to its crash site. Three days later, Truth or Consequences is under quarantine. Several members of its populace are dying from a mysterious virus. Boyd later shows up at the Sierra County Hospital, his body covered in red spikes, and eyes now turned red.
A week later, Rainbow Operator Eliza Cohen arrives at the now ravaged town, the National Guard now holding position against the virus. After assessing the situation, she asks Six to allow Team Rainbow to engage the threat and requests additional support from other Operators to assist in controlling the pandemic. Amongst the selected are James Porter, Jordan Trace, Gustave Kateb, Timur Glazkov, Maxim Basuda, Alexsandr Senaviev, Marius Streicher, Sebastien Côté and Siu Mei Lin. Two CBRN specialists from the GIGN and Spetsnaz CTUs are also recruited to combat the threat: Olivier Flament and Lera Melnikova.
Rainbow is sent to Sierra Paradise, which had turned into a nursery for the virus. Thermite developed specialized Nanothermite Charges to specifically destroy it. However, complications arise when Jäger, the team's pilot, and his helicopter are suddenly struck down, forcing the on-site team to rescue him.
Sierra Veterans Wing
Doc proposes the rescue of Dr Ellen Mackintosh, a survivor of the Outbreak who was caught in the middle of the virus. Although initially believing the mission to be too dangerous, Ash is convinced by Doc that Dr Mackintosh may help solve the Outbreak, if the doctor does have a clue to a cure.
Ash and Tachanka discuss the origins of the virus. By searching online, Ash was able to find its origins to a Soviet-era capsule, as there was an attempt for it to be sold online by Boyd Brooks. Thus, she asks Tachanka to contact the Russian government for a background check on the capsule.
Due to the type of threat involved, only a few Operators are available. Along with the Recruit, the following Operators have been selected to quarantine the area:
Outbreak features five different types of Roaches, the people who are infected with the Chimera virus.
- Grunt: Common enemies that become more durable when they are actively hunting the on-site team. Can be heard talking when undisturbed.
- Breacher: Highly-volatile enemies that can blow up walls, even those that are reinforced. Easy to spot with its bright yellow color. If they are hit at melee range when they are about to explode, they will become disorientated, giving the Operator enough time to escape as they end up exploding anyways.
- Rooter: Special enemies that launch coral spikes for attacking and trapping. Becomes stronger near death.
- Smasher: Large, durable roaches that have mutated so heavily their armor is basically impenetrable through normal means. These enemies can charge at a rapid pace, but are also blind. It can run through unreinforced walls with ease but have a weak spot in the form of a red, glowing gash on its back. Smashers can be provoked into charging by constantly shooting, and they may run into obstacles or walls and become stunned, rendering it temporarily vulnerable to melee takedowns from the back. They take up to three of these "backstabs" before they die.
- Apex: The "leaders" of the Roaches that call in waves of hostiles. Those that it spawn in are stronger than normal Grunts and Breachers. They can also shoot blinding projectiles that prevent Aiming Down Sights.
With the exception of Smashers, headshots are more effective than shots to the Roaches' bodies. Depending on the type, Roaches may take several headshots to kill; Apexes are especially tough in this regard. The three former types can be taken down when flashed. Melee is generally ineffective for killing except when takedown prompts appear. Grunts and Breachers can be pushed back with a melee strike.
- Ubisoft hid clues about Outbreak in Oregon, Presidential Plane and Kafe Dostoyevsky. An incomplete QR code in Oregon went to a site called Rainbow Leaks. The site's full contents have since been unlocked.
- Each of these "Files" are centered around a conspiracy theory that "Outbreak" may be a false flag by the FBI. Members of the leak group are referred to as "Facters".
- According to the Oregon files, the parasite reduces pain in victims by supercharging their adrenal glands.