Extra Ops are event-oriented modes with cooperative elements in Metal Slug Attack, first introduced in 1.4.0. The player is presented with stages that cost Sortie Points to play and give MSP, Unit Parts, and unique Event Items as drops, while also generating Exclusive Points.
Extra Ops types
The Extra Ops have a variety of types, each with unique features. Some appear regularly, and some have been entirely superseded by other types - for example, Score Attack Extra Ops were replaced by Snatch Wars Extra Ops, which were in turn replaced by Try Line Extra Ops. The very first type of event to appear in the game, Marathon Extra Ops, still often appears as the first for each month.
|Marathon||Single-player||Players work their way across multiple maps, covering three different difficulty levels.|
|Rare Boss||Single-player||A "rare boss" randomly appears as players beat stages, granting access to special unit parts.|
|Score Attack||Competitive||The final enemy gains power the more times it is beaten. At the end of the event, boss parts are awarded to the highest-scoring players.|
|Daily Ranked||Competitive||Prizes are awarded to the highest-scoring players at the end of each day.|
|Snatch Wars||Guild-based||Guilds fight for control of the map. Boss parts are awarded to the groups holding the largest areas at the end of each day.|
|Try Line||Guild-based||Coins are gained as guilds work their way towards the center of the map. Prizes are purchased from the Try Shop.|
|United Front||Co-operative||Players fight together to gain coins. Prizes are purchased from the United Shop.|
|Crank Key||Co-operative||Players work to defeat enemies, acquiring crank keys as their combined kill counts grow higher.|
The Ops types also determines the nature of the equippable Event Items used by introduced units. Marathon and Rare Boss EOs have non-craftable silver items. This means the items are only available through that EO until it is released on Another Story. Ranked EOs (both normal and daily) have craftable silver items, meaning that even after their EO is over, the exclusive items can still be created with normal items, but will take longer than usual to complete. Guild Ops bosses except Try Line do not have any unique items of their own and instead rely on normal items to unlock their skills.
Exclusive Points are a currency exclusive to this mode, however they cannot be spent directly and reset at the end of each event. Instead they are used as a unit of measure, rewarding the player for reaching specific milestones. EPs are generated depending on mission outcomes, as well as Completion Rank, and are further influenced by presence of Expert Units in the active deck and use of Reward Up (percentages affect the base values of EP rewards for any given stage). Expert Units can be set up at the Soldier Camp for guild mates to use (bonuses from duplicate units stack) - each unit can only be hired once a day from other players.
The icon representing EP changes depending on the event, though it retains its distinctive silver disc appearance.
Certain units are flagged as "experts" during each event, and add extra Exclusive Points at the end of each mission. These flash while building your deck, making them easy to spot.
Exactly which units are experts depends on the current event. Typically the selection includes:
- Current Super Rare pre-acquisition / box / step unit (highest bonuses)
- Current Rare pre-acquisition unit / Pack Shop (second highest bonuses)
- Last month's Super Rare and/or Rare pre-acquisition unit (slightly lower bonus)
- Previous Extra Ops boss (lower bonuses)
- Various units, typically a max of 3 (lowest bonuses) - usually, the Rare unit that can be unlocked in the EO is one of these expert units.
Pressing the Expert button in the Extra Ops menu displays icons next to the current set of experts:
|Increases points gained per victory by X%.|
|Unit has increased power and costs less AP to deploy. Best experts have higher AP reduction.|
|(Daily Ranked only) - Increases the chance of golden enemies appearing each stage.|
|(Snatch Wars / Try Line only) Increases the damage of all units in that deck.|
|(Score Attack only) - Soldier moves further with each victory (bosses may be fought more often).|
|(Rare Boss only) - Rare bosses appear more often.|
|Game Modes||Another Story | Attack! • List of Standard Missions • List of Elite Missions | Battle and Team Battle | Combat School | Extra Ops • List of Extra Ops | Online | P.O.W. Rescue | Rank Match | Special Ops|
|Features||User Profile | Level and EXP | VIP | Build Up | Units • by Icon • Teams • Unobtainable | Stats | Items • by Stats • Event Items | Guild • List of Guild Raid Stages | Daily Login | Daily Quests | Events | Power-Up | Quests | Mystery Crank | Treasure Hunt | Shops | Dream Lottery | Beginner Support Campaign|