Metal Slug Defense Wiki

Unit are the defense and the offense of your base, they are your main tool (or troops), these units are created from AP during combat. These units can be upgrade with MSP to enhance damage they deal and to increase Their HP. Many units can be obtained through the shop menu, however, the currency to buy them with are Medal.

How to Obtain Units

Units can be obtained in several ways.

  • Many units can be bought from the shop for a certain number of medals. There are occasional sales in some updates where the units that cost 200+ Medals can be bought at half price.
  • Some units are unlocked upon completing tasks in the Sortie missions. Some are unlocked after completing an area, some are unlocked after rescuing all POWs in an area, and some are unlocked in the shop after completing an area or world.
  • Seven units are unlocked by rescuing the POWs in the daily boss area (in the Alternate World) which changes according to the day of the week.
  • Twelve units are unlocked by saving all the POWs in the Emergency stages, which appear on the main map in sortie mode at specific times of the day (12:00 nn 6:00pm, 10:00 pm). The units must be unlocked in sequence.
  • Some units are only available in events that are exclusive to specific updates. Most events are accessible under the EVENT tab in Sortie mode. The unlocking criteria varies depending on the event. These units are listed on this page.
  • Certain updates do not involve the EVENT tab but instead open special stages on the world map that are involved in unlocking new units (e.g. Halloween Soldier, Rugal Bernstein).
  • For some KOF Units, they can be bought in bundles of three with real money.


Units can be sorted by their characteristics and the type of unit they are. If the player sorts the units in their respected faction, all unit in the slot will receive a 10% HP bonus.

Damage Type

  • Spread: Units that can harm units over an area of effect.
  • Single: Units that can harm only one unit at a time with its attack.


  • Light Units: These units can be knocked back by attacks and will be run over by Metal Slug Attacks. Some of these units can actually survive the damage blast of the Metal Slug Attack but not the attack itself, such as Christmas Fio. Nearly all groundunits that cost under 100 AP are in this category. Examples of units that cost more AP but can be run over include Christmas Eri/Fio, Clone Fio(Zombie), Robert and King. Cat Mini UFO is a special case, as it cannot be knocked back and is a ground unit, but is run over by Metal Slug Attacks.
  • Heavy Units:These units will take a Metal Slug Attack and stop it, and can be knocked back by attacks. Most units are in this category. The actual resistance to knockback varies among this group: units like Vanguard and Di-Cokka will get knocked back by any attack that has the power to do so, while units like Brian Battler and Allen O'Neil(Wrath) resist knockback until their HP drops below a certain percentage.
  • Tank Units: Units with high HP that do not get knocked back when they are hit. They can stop a Metal Slug Attack without being knocked back. This may work against them as some multi-hitting attacks will hit them more than they would a Heavy unit. Examples include Iron Nokana, Augensterm, Mars Mecha and Smasher.
  • Air Units: Units that fly very high to evade nearly all ground attacks, and cannot be knocked back. These units do actually have resistance values but most are impossible to hit with Metal Slug Attacks, with the exceptions of certain large air bosses and air units that dip during their attacks. Examples of Light air units that can be run over when they dip include Mini U.F.O and Huge Locust, while examples of Heavy air units that can block Metal Slug Attacks are Dai-Manji, Sol Dae Rokker, and Slug Flyer.

Special Abilities

  • Summoning: The unit can Generate new Units. Some units are solely for generating (e.g. Crab Nest, The Snail House) while others turn into a different unit upon destruction (Emain Macha, Forklift, Protogunner).
  • Transformation: The unit changes its properties when its special is used (Nadia, Slug Trolley, etc...), or when its HP drops below a certain value (Allen O'Neil Jr., Big John, etc...).
  • Self-destruction: The unit can destroy itself to deal damage and not award any AP to the opponent. Some units exist solely for this purpose (Hopper Mecha, Zombie(Rebel Soldier), Mutated Soldier) while others can attack normally and self-destruct with their special attacks (Cat Slug, Samurai Infantry(Red)).
  • Attacking after death: The unit will attempt one last attack after its HP drops to 0. Examples include Samurai Infantry(Red), Dangling Snail, and Rugal Bernstein.

Unlock Units


World 1

Area 1: Southeast Asia- Marco

Area 2: East Asia - Tarma

Area 3: Africa - Fio

Area 4: Central Asia - Eri

Area 5: Dr. Maureau's Island: SV-001

emergency area 1(free all POWs): 3-Ton Utility Truck

emergency area 2(free all POWs): Di- Cokka

emergency area 3(free all POWs): NOP-03 sarubia

emergency area 4(free all POWs): Hopper Mecha

World 2

Level 4: Shoe & Karn

Level 6: Iron Nokana

Level 8: Man Eater

Level 9: Monoeye

Level 10: Jupiter King

Level 11: Slug Gunner

Final Level: Ring Laser Mecha and Mars Mecha

Emergency Area 1 (free all POWs): Abul Abbas

Emergency Area 2 (free all POWs): Allen O'Neil

Emergency Area 3 (free all POWs): Donald Morden

Emergency Area 4 (free all POWs): Mars People

World 3

emergency area 1(free all POWs): Elite Arabian Soldier

emergency area 2(free all POWs): Cyborg Allen O'Neil

emergency area 3(free all POWs): Morden Robot

emergency area 4(free all POWs): Mars People Cadre

Another World

Vietnam (Only appears on Mondays): Fat Marco

Kazakhstan (Only appears on Tuesdays): Fat Tarma

Galapagos Islands (Only appears on Wednesdays): Fat Eri

South Africa (Only appears on Thursdays): Fat Fio

Russia? (Only appears on Fridays): Slug Copter

(Only appears on Saturdays): Flying Tara

Saudi Arabia (Only appears on Sundays): Samurai Planes