Extinction

Extinction is a game mode featured in Call of Duty: Ghosts. The game mode features up to four players fighting aliens in a post-apocalyptic world. Players have objectives, which are to destroy alien Hives and complete Challenges. Players also earn money by killing aliens, destroying Hives or searching Search Piles. The money earned from these can be used to purchase additional guns placed through out the map (similar to Zombies) and use abilities selected pre-game.

The traps that can be used against the aliens are the electrical fence and fire trap. The traps cost money to set and only last for a short period of time. The traps do not have a cooldown time and can be used as often as the player wants provided they have the money needed.

There are four classes for the player to choose from, Weapon Specialist, Tank, Engineer, and Medic. For each class there is a specific set of unique abilities/perks that the player will be able to utilize for themselves or their team. There is also loadout slots that players can choose different options from including: Pistol, Ammo Type, Team Support, Strike Package and Equalizer, the player also passively has On the Go and Resilience. Once the player completes level thirty, they will automatically prestige, allowing them to equip an additional Relic, once per prestige. The mode is not infinite round based like Zombies but has an ending and is much more linear, although the ending is optional.

If a player receives enough damage they will fall to the ground (frequently referred to as "down"). During this period of time the player still has the option of using their secondary weapon. However, another teammate must revive the fallen teammate or they will bleed out and die. When a player dies they will be in spectate mode and a dog tag will appear where their body was located. Nevertheless, it is still possible for another player to revive the dead player at their dog tag. In solo, at the start of the game, the player can be downed once and revive themselves after a couple of seconds, but next time they will directly die. However, when a barrier hive is destroyed, the player receives an extra chance; this means that the player can be downed a maximum of 3 times in a single game before dying.

Money System
The maximum money a player can carry is $6000 ($3000 with the Smaller Wallet Relic, $8000 with the +4 Engineer upgrade or $4000 with both). The player will receive money after a Hive is destroyed, based on their score earned while it was being destroyed. A supply drop of $3000 ($2250 with Smaller Wallet Relic) will be dropped after a Barrier Hive is destroyed.

The base money gained is determined by the type of enemy killed and is then multiplied by how or where the enemy was killed. If two of the same type of multipliers apply then only one applies to the money given, if a positive and negative multiplier apply then the base money is given. An additional multiplier of 0.3x is added to any alien that spawns in the Cabin area of Point of Contact after the first Hive in the Cabin area has been destroyed.

Positive multipliers:
 * 1.5x: Killed with a critical hit
 * 1.5x: Killed with melee

Negative multipliers:
 * 0.75x: Smaller Wallet Relic
 * 0.5x: Killed with a hit to the armor (Does not apply with Armor Piercing Ammo)
 * 0.5x: Assisted kill

Maps

 * Point of Contact
 * Nightfall

Enemies

 * Scout
 * Hunter
 * Scorpion
 * Seeker
 * Rhino
 * Leper

Ranks
Rank unlocks:
 * Rank 2 - Stun Ammo
 * Rank 3 - Tank - Multiplayer Background
 * Rank 4 - Feral Instincts
 * Rank 5 - Engineer
 * Rank 6 - Grenade Turret
 * Rank 7 - .44 Magnum
 * Rank 8 - Armor
 * Rank 9 - Mortar Strike
 * Rank 10 - Medic
 * Rank 11 - Multiplayer Background
 * Rank 12 - Incendiary Ammo
 * Rank 13 - M9A1
 * Rank 14 - Team Booster
 * Rank 15 - Crowd Control
 * Rank 16 - MP-443 Grach - Multiplayer Background
 * Rank 17 - Random Supplies
 * Rank 18 - Trinity Rocket
 * Rank 19 - Multiplayer Patch
 * Rank 20 - Explosive Ammo - Multiplayer Background
 * Rank 21 - Multiplayer Background
 * Rank 22 - Sentry Gun
 * Rank 23 - MK32 Grenade Launcher
 * Rank 24 - Multiplayer Patch
 * Rank 25 - Armor Piercing Ammo
 * Rank 26 - Multiplayer Background
 * Rank 27 - Multiplayer Patch
 * Rank 28 - Vulture
 * Rank 29 - Minigun

Achievements/Trophies
No Man Left (20 / Bronze Trophy ) - Escape with all four players

Sprinter (20 / Bronze Trophy ) - Reach the exfil chopper with 1 minute and 30 seconds or more remaining on the clock.

Made it Out Alive (20 / Bronze Trophy ) - Escape 1st time

Completionist (25 / Bronze Trophy ) - Complete all Extinction challenges and escape.

Cabin Fever (10 / Bronze Trophy ) - Make it to the cabin.

City Dweller (20 / Bronze Trophy ) - Make it to the city.

Any Means necessary (40 / Bronze Trophy ) - Get 50 kills with the electric fence and fire traps in a single game.

Trash Picker (20 / Bronze Trophy ) - Scavenge 40 items in a single game.

Throttled Escape (10 / Gold Trophy ) - Escape using a relic.

Trivia

 * The aliens were first seen shortly after the ODIN strikes that occurred at the beginning of the Ghosts campaign.
 * Extinction marks the first appearance of aliens as enemies in the franchise.
 * Skill points spent in one game do not carry over to the next. Each classes skill set is reset at the start of every game.
 * The soldier the player plays as will point out when a new alien type is spotted.
 * While downed, the player is still able to move turrets and the I.M.S..
 * When reviving another player, the player can rotate their character while still reviving the downed player.
 * The player is still able to move while being revived or while repairing the Drill.
 * If a player dies they will only lose their tactical & lethal equipment.
 * The player can drop money in increments of $1000 by holding the ADS and jump buttons for two seconds.