Jump to Combat Strength Modifications


A unit can't enter a tile occupied by an enemy unit. Instead, it will ask if you want to attack. Combat usually locks units in battle until one is destroyed. An attack costs the aggressor one move-point. It will also lose moves proportional to damage it suffers. Attacking a tile does not move there — the surviving unit remains where it was.

Some combat rules are obvious—units must have non-zero attack strength to attack. Defenders with zero defense lose immediately. There are limits on which units can attack which others. Most Land units can only attack other Land units. Most ships can attack other ships and also Land units. Helicopters and Marines can attack Land and Sea units and can be attacked by most units. Bombers and Missiles can attack any Land or Sea unit. Fighters and Anti-Aircraft Artillery can attack almost all units.

Fighters in a city or a Base can be attacked by land. Ships in port cities suffer defense penalties. Marines can attack targets from aboard ship or Helicopter; other Land units must disembark and wait one turn before engaging enemy units (unless the ship first docks on a tile where Unloading and Deboarding is legal.


A unit ordered to Sentry remains in place indefinitely and no longer asks for orders each turn. Sentried units can be reactivated manually by selecting them, or activate automatically if an enemy unit comes into view (or if they have finished healing.) Sentried units will report on the first non-allied unit they see moving within their vision or 3 tiles of their location (whichever is less.) Sentried units get no defense bonus.


Land units can be ordered to Fortify, which gives an extra defense bonus for the unit if it is attacked next turn and had at least remaining move point left to fortify. Once fortified, units enjoy the same +50% advantage as land units in a city. A unit with zero move-points can't fortify—it needs remaining move-points to begin the next turn fortified. Unless specified otherwise, a unit who moves, attacks, or does a Special Unit Attack will lose its fortified status and have to re-fortify over turn-change to gain it back. The exceptions are a few units whose special tactics allow them to preserve their fortified state. The Phalanx and Marines can do Special Unit Attacks and Standard Attacks without losing fortified status. Archers are able to do Volley Attacks without losing fortified status, but not Standard Attacks.

Spies in combat. Spies can harm enemy units by doing sabotage.

Combat Mechanics[]

There are two types of combat: Standard Attacks, which are the majority of all combat; and Special Attacks, which are special tactical engagements.

Standard Attacks[]

Each unit begins combat with one or more hitpoints—the amount of damage it can sustain. (See Units for stats on each unit type.) Combat consists of successive rounds of violence between the units, which cannot be interrupted and ceases only when a unit dies by reaching zero hitpoints. (An exception is most ancient sea units—they can attack for a maximum of 15 combat rounds.) In each combat round, only one unit succeeds in wounding the other. The damage a unit inflicts with each blow is called its firepower.

In each combat round, which unit inflicts damage is based on probability. The attacker's chance is relative to its attack strength, while the defender's chance is relative to its defense strength. For example, on an open field with no other bonuses: Archers have attack strength 3 and attack a Phalanx with defense strength 2. For each round, the Archers will have odds of inflicting damage, while the Phalanx has odds.

Special Unit Attacks[]

These are unique tactical engagements different from the standard "to-the-death" fatal combat. SUA are typically—but not always—ranged attacks which gain the advantage of not incurring retaliation, but (usually) at the cost of not doing fatal damage. In spite of usually not being fatal, such special attacks are quintessential to the science of Tactics. They can affect enemy movement points and limit their ability to gain strategic positioning. SUAs may cause injury or fatigue that may have decisive results when followed up with standard combat. They may degrade or compromise large numbers of enemies at little or no cost. In MP2D, a handful of special units have Special Unit Attacks to replicate the historic tactical abilities that these units famously exploited for advantage. Phalanx, Archers, Legion, Siege Ram, Catapult, Ballista, Cannon, Artillery, Howitzer, Magnum Turret, Zealots, Fanatics, Marines, Zeppelins, and Battleships, have different types of SUA that emulate the historic abilities of those units..Note: You can see the statistics for any SUA by hovering the mouse over the menu button for the Special Unit Attack.

Unit Attack Type Combat





>1 ?















All Standard Attack to death 1 1 all
Phalanx1 Rumble 3Fortified 5/9 1 1
Archers Volley 2Fortified 1 5/9 3
Legion Pilum 1 @ 1 2 2
Siege Ram Attack City Walls 1 1/9 1
Siege Ram Ram Fortress 4 @ 8¾× 1 5/9 1 all
Catapult Bombard 4Fortified all 2 1 1
Ballista Ranged Attack 5 all 2 2 2
Cannon Bombard 5Fortified all 2 2 1
Artillery Bombard 6Fortified all 2 3 1
Howitzer Bombard 7Fortified all 4 4 1
Magnum Turret Bombard 7Fortified 1 2 5 2
Zealots/Fanatics2 Skirmish 3 1 5/9 4
Marines3 Bazooka 3Fortified 1 5/9 2 1
Zeppelin Bomb 4 2 2 1
Battleship Bombard 3 5 2 4 1

= unit can stay fortified while making the Special Unit Attack.

  1. Phalanx:
    • Cannot be transported, must be on native Land terrain.
    • Must be Fortified OR have not moved this turn, to be able to Rumble Attack.
  2. Zealots and Fanatics
    • Can only Skirmish Assault while under leadership of Theocratic government and in domestic territory.
    • Can Skirmish Assault conquered cities which still have Foreign National populations.
  3. Marines cannot Bazooka Attack unless V2 "Hardened" or higher.

Special Unit Defense[]

Just as some units can do Special Unit Attacks, other units' tactical abilities let them retaliate against units that expose their location via ranged attack and other forms of SUA. Special Unit Defense (SUD) is an exception to the rule that Special Unit Attacks have no risk of retaliation. When attacked from range, these units can do a SUD retaliation attack against the location the attacker exposes by making the attack. The following units can retaliate against special unit attacks with SUD: Archers, Catapult, Cannon, Artillery, Howitzer, Battleship, Helicopter. Archers, Ballistic Units, and Battleships are the only units that can do both SUA and SUD.

Unit Combat






Archers 2 3 -
Catapult 4 1 1
Ballista 5 2 2
Cannon 5 2 1
Artillery 6 3 1
Howitzer 7 4 1
Magnum Turret 7 5 2
Helicopter 3 3 1
Battleship 3 4 1

NOTE: The requirements for Special Unit Defense are the same as for Special Unit Attacks and regular Attack: all three actions require a unit to have moves left in order to do it.

Tired attack[]

When units do standard attacks or special unit attacks with less than one full move-point, they are penalized because of tiredness. Only a fraction of their attack strength is used. If they have move-points, they will attack with strength. If they have move-point, they will attack with strength, and so on.

There are other factors which affect combat strength. These are summarized in the tables below:

Combat Strength Modifications[]

Veteran Bonuses[]

The veteran level of a unit may give it bonuses to combat strength.

Veteran Bonus
Unit is not veteran ("green") ×1.00
Unit is veteran 1st level ("veteran") ×1.50 V1
Unit is veteran 2nd level ("hardened") ×1.75 V2
Unit is veteran 3rd level ("elite") ×2.00 V3
Unit is veteran 4th level (elite-2, "crack") ×2.10 V4
Unit is veteran 5th level (elite-3, "master") ×2.20 V5
Unit is veteran 6th level (elite-4, "champion") ×2.30 V6

Standard Modifications[]

Many game elements may result in modifications to combat strength for attackers and also defenders:

Standard Combat Modifications
Terrain Defense Bonuses, TM × TM
Terrain includes a River, add to TM +0.50
In city with Fortifications on Difficult Terrain, add to TM +0.33
...In city with Fortifications on Flatland, add to TM +0.50
Unit is tired (move points < 1) ×(moves left)
Phalanx or Pikemen attacking and attacker owns the Agōgē of Sparta ×1.5
In city with SAM Battery against Air units (not Stealth or Missile)... ×2
.... In city with SAM Battery against Stealth Air units ×1.25
In city with SDI Defense against Missile ×2
In city with Coastal Defense against Sea units ×2
In city with City Walls against Land unit that is not Ballistic class ×2
.... In city with City Walls against Units.mp2d#Catapult ×1.75
.... In city with City Walls against Cannon or Artillery ×1.50
... In city with City Walls against Howitzer ×1
Land unit/Fighter/Helicopter in Fort against Land or Sea (not Armor) ×1.33
Fighter in Fortress against Land or Sea units (except Armor) ×1.33
Land unit/Heli in Fortress against Land or Sea units (except below...) ×2
... Land unit in Fortress against Armor I, Helicopter, or Air units ×1.66
Sea unit in Naval Base. ×2
Land unit fortified or in city * ×1.5
* Units able to fortify get that bonus free in cities, even if not fortified..
  • The above factors are combined: Each factor that qualifies as true is multiplied into the final bonus.
  • Naval Base, Castle, and Bunker are all Fortress-types and give the same defense bonus to land units.
  • The Bases page gives a chart for the base bonuses above.
  • Also see: Terrain bonuses and base bonuses.

Special Modifications[]

There are more circumstances that result in adjustments to combat strength:

Special Combat Modifications
Pikemen defends against mounted units (except Cavalry) Defense strength ×2
AEGIS Cruiser defends against Aircraft, Missile or Helicopter Defense strength ×3
Missile_Destroyer defends against Aircraft, Missile or Helicopter Defense strength ×2
AAA or Mobile SAM attacks or defends vs Aircraft or Helicopter Strength ×2
Mobile_SAM defends vs Missile Defense strength ×3
Armor II defends against Missile Defense strength ×1.75
Stealth Aircraft attacks against units with Anti-Air bonus Attack strength ×1.25
Fighter attacks a Helicopter Helicopter firepower reduced to 1

Helicopter defense strength ×½

Ship defends while inside city: "Pearl Harbor Effect" Attacker firepower ×2
Ship firepower reduced to 1
Sea unit attacks Land unit (see Shore Attacks) Both have firepower reduced to 1
Sea unit defends against Marines Defense strength ×2
Cruiser,Battleship,Missile Destroyer,Aegis Cruiser defend vs Submarine Defense strength ×2
Destroyer defends against Submarine Defense strength ×4
Knights defend against mounted units (except Cavalry) Base Defense = 3

Shore Attacks[]

Sea units attacking the shore are subject to different dynamics:

Shore Attacks (Sea unit vs. Land unit on Shore)
Combat Rounds 20
Attacker Firepower 1
Defender Firepower 1
Attacker chance of promotion -50%
Attack Strength for FP2 ships ×1.33 attack adjustment for FP2 ships -33% attack adjustment for FP1 ships none
  • For all modern ships that aren't River Ships; in other words, from Ironclad onward:
    • Battle lasts 20 combat rounds, which may or may not result in a victor.
    • Chance of attacker promotion is reduced by half.
  • For ships with Firepower:2 (Cruiser onward):
    • Combat Strength is adjusted during Shore Attacks:
      • Firepower of Attacker and Defender are set as Firepower:1.
      • Attack strength increased +33%
      • Overall effect is -33% reduction in attack strength for 2FP sea units, (was -50%)


General Promotions[]

Most units have a chance to gain a higher veteran level when they survive combat. Higher veteran levels impart different kinds of bonuses to units:

  • Movement bonuses. Veteran levels may impart a movement bonus.
    • Crack V4 land units gain + move-point over standard.
    • Air and Sea units gain +1 move-point over standard.
    • Scouts and Marines gain +²⁄₉ move for every veteran level.
  • Work-rate bonuses. Workers II and Veteran military units who are able to work tiles apply their vet bonus to their work-rate.
  • Ability bonuses. Rarely, special abilities are unlocked from veteran levels. For example, Marines can do Bazooka attacks after achieving V2.
  • Combat bonuses. All veteran military units gain veteran bonuses to their Combat Strength. With two exceptions, all combat units have the following chances of promotion:

Promotion Odds for Land and Sea units[]

Land and Sea Units: Veteran Promotion Chances
V0→V1 (Green to Veteran) 50% V1
V1→V2 (Veteran to Hardened) 33% V2
V2→V3 (Hardened to Elite) 20% V3
V3→V4 (Elite to Crack) 15% V4
V4→V5 (Crack to Master) 15% V5
V5→V6 (Master to Champion) 15% V6

Promotion Odds for Air units[]

Offensive Air units' promotions are slightly lower, to balance getting more attacks per turn. Defensive air units have standard promotion rates.

Air Units: Veteran Promotion Chances
V0 (Green to Veteran) 40% V1
V1 (Veteran to Hardened) 25% V2
V2 (Hardened to Elite) 16% V3
V3 (Elite to Crack) 10% V4
V4 (Crack to Ace) 10% V5
V5 (Ace to Top Gun) 10% V6

Promotion Odds for Marines[]

These higher odds represent and simulate foot soldiers' upgrades to modern weaponry as the game progresses:

Marines: Veteran Promotion Chances
V0 (Green to Veteran) 60% V1
V1 (Veteran to Hardened) 50% V2
V2 (Hardened to Ranger) 40% V3
V3 (Ranger to Commando) 30% V4
V4 (Commando to Green Beret) 20% V5
V5 (Green Beret to Navy SEAL) 15% V6

Marines' veteran bonuses represent improved strength of weapons and special ops forces in the late game:

Veteran Combat Strength Multiples
V0 (Green) 100%
V1 (Veteran) 150% V1
V2 (Hardened) 175% V2
V3 (Ranger) 250% V3
V4 (Commando) 300% V4
V5 (Green Beret) 350% V5
V6 (Navy SEAL) 400% V6

Note: 1. Marines are the strongest foot unit, yet come in the middle of the tech tree. Rather than upgrade to a newer unit, the game represents the need for experience and training for modern special ops. 2. A veteran Marine usually needs 5 battles to become Ranger, where it can defend slightly better than older cheaper faster Alpine Troops. 3. A veteran Marine requires 20 successful battles on average to become Navy SEAL, a rare unit attacking at 89% the strength of a green Howitzer. 4. Thus, the late bonuses serve to slightly mitigate the rapid uselessness that occurs for late-game foot units; and provide a role for multipurpose special ops in modern warfare.

Injured Movement[]

Damaged Land and Sea units begin each turn with fewer move-points than normal. Their move-points will be proportional to (current_hitpoints / total_hitpoints). However, each unit class is guaranteed a minimum amount of moves: this is referred to as min_speed. Land units have a min_speed of 1. Ships made from wood have a min_speed of 2. Modern metallic ships have a min_speed of 3. Aircraft suffer no min_speed losses and always keep 100% of their move points.


Damaged units enter combat at a disadvantage. Most recovery effects need units to spend a whole turn not moving or attacking.

Units recover hitpoints each turn according to the table below:

Healing Factor Modifications
Resting unmoved *additional +10%
Fortified unmoved *additional +10%
In a City unmoved *additional +33%
in Fortress: Land or Helicopter unit unmoved *additional +25%
in Fort: Land units only unmoved *additional +10%
in Airbase: Aircraft unmoved *additional +20%
in Airbase: Helicopters unmoved *additional +25%
Land unit in city with Barracks unmoved Completely restored
Sea unit in city with Port Facility unmoved Completely restored
Air/Helicopter unit in Airport city unmoved Completely restored
Unit is a Ship (see chart below) *additional +10%
Helicopter in a city, moved or unmoved *total: +10hp
Unit in a city which got no other bonus +1 hp
  • All healing factors requiring "unmoved" add with each other. For example,
    • A fortified unit gets +10% for resting unmoved and +10% for being fortified = +20%.
    • A unit in a Fortress would get +10% resting unmoved + 25% fortress = +35%
    • A fortified unit in a city would get +10% resting unmoved +10% fortified +33% city = +53%.
  • If you sentry a damaged unit, it becomes active and asks new orders when it's restored.
    • A fortified unit will do the same, but only if it's in a city where it can't lose its fortify bonus.
  • Except as noted below, all healing factors need a whole turn resting unmoved.
  • Bonuses marked with do not require the unit to be resting unmoved for a whole turn.
    • Note that +10hp for a Helicopter in a city is the total of all its repair bonuses: not cumulative to any others.

Crew repairs[]

Crew repair restores ships +10% every TC regardless of whether the unit has moved.

Crew Repair
Ship type Repair rate
10hp 1hp
20hp 2hp
30hp 3hp
40hp 4hp

Producing Veteran Units[]

You may produce new V1-Veteran units in a city if it has the appropriate building for its type:

Barracks i Barracks cost:30 upkeep:1

requires:Warrior Code makes vet. Land units

Barracks ii Barracks II cost:35 upkeep:1

requires:Gunpowder makes vet. Land units

Barracks iii Barracks III cost:40 upkeep:1

requires:Mobile Warfare makes vet. Land units

B.port facility Port Facility cost:60 upkeep:3 requires:Amphibious Warfare

makes vet. Sea units

B.airport Airport cost:120 upkeep:3

requires:Radio vet. Air & Missile units

*Marines made in a city with Barracks III, Port Facility, AND Airport come out V2. Sun Tzu's War Academy gives an additional +1 veteran level to Land units. Magellan's Expedition gives an additional +1 veteran level to Sea units.


A "stack" is the term for multiple units on a single tile.

One unit defends a stack[]

When several units on the same tile are attacked, the unit most capable of defense protects the entire tile.

  • More precisely, for all defenders on the tile which can defend against the attacker, winning chance is calculated to the precision of 0,001­%, and the best result is chosen to defend the whole stack. If several units have similar results, the cheapest unit defends first.


A lost battle only kills one defending unit if the defenders are inside a City or Base. Otherwise, the loss of a defender usually results in Stack-Kill: the loss of every attackable unit on the tile. Some exceptions to the Stack-Kill rule are below:


Stack-Escape simulates the ability of Air and Sea units to escape in multiple directions if "faster" than the attacker.

Air and Sea units (from Galleon onward) can sometimes survive a Stack-Kill event. When they are present in a stack whose defender has died, each has a separate 60% chance to escape to an adjacent tile if and only if it doesn't have less moves left than the attacker. For example, if an attacker with 2 remaining move points kills the defender of a stack, each defending unit in that stack needs 2 or more remaining move points to qualify for a chance to escape.

  • Escape Charm is an extra 1% bonus awarded for each surplus move point the defender has over the attacker.
  • For example: if a Submarine with 1 move point kills a stack, then a ship with 5 move points receives an Escape Charm of 5-1 = 4%. The ship has a 64% chance of Stack-Escape.

Note: Destroyer types and Stealth Aircraft have base odds of 67% to stack escape. Submarines get a 75% chance. Satellites always stack escape.

Stack Chief[]

A unit with the Stack Chief flag will never die when another unit in its same stack dies. Units with the Stack Chief flag are the Battleship and the Carrier.

Lost Cargo[]

When a unit transporting other units is in combat, only the attacking unit participates in the engagement, and its passengers are lost if it loses.

Battles in Cities[]

City Population Loss[]

When a City loses a defending unit to an attack by a Land unit, there is a 50% chance that a city citizen will be lost if the city has no Fortifications or City Walls1, 2. Once the last defender is gone, you may conquer the city with a Land unit or Helicopter. Ships and aircraft can attack cities but not capture them.

1 Knights do not cause population loss.
2 The server setting killcitizen_pct regulates the chance of one citizen being lost, and defaults to 50%

Conquered Cities[]

  • A captured City:
    • loses 1 population, which destroys1 the City if it is size 1.
    • Units which belong to the conquered city and are not in other domestic cities, have a chance of disbanding. (See table below)
    • Upon capture of a City, each building has a chance of being destroyed, depending on the type of building, the conqueror's government, and whether the city is being liberated. (See table below)
    • The victor may steal technology blueprints from the former owner.
1 Knights do not cause population loss.

Units supported by conquered cities[]

When a unit loses its Home City from conquest, there is a chance that it will Disband, which means it abandons your country and disappears from the game. If the unit is inside another of your cities, it will not disband: it will re-home in its current city if legally able.

Disband Odds when units lose their Home City
Victim's government Re-home Disband
Anarchy Anarchy 0% 100%
Despotism Despotism 25% 75%
Monarchy1 Monarchy 35% 65%
Monarchyconstitutional Constitutional Monarchy 55% 45%
Communism Communism 55% 45%
Republic Republic 65% 35%
Nationalism Nationalism 65% 35%
Democracy Democracy 80% 20%
Theocracy Theocracy 90% 10%

* Nuclear units have a 25% higher chance to re-home, i.e., 25% less chance to disband.

Razed Buildings[]

When a city is conquered (or liberated by its original owner), destruction and looting may result in buildings and wonders being lost.

Odds for each building to be razed during conquest
Victor's government base chance liberation
Anarchy Anarchy 21% 10%
Despotism Despotism 21% 10%
Communism Communism 21% 10%
Monarchy1 Monarchy 14% 7%
Monarchyconstitutional Constitutional Monarchy 14% 7%
Republic Republic 14% 7%
Nationalism Nationalism 14% 7%
Democracy Democracy 7% 3%
Theocracy Theocracy 7% 3%

* Odds of razing are half if liberating an originally founded city.

Certain buildings have only half the odds of being razed:

  • Contentment Buildings:
    • Amphitheatre, Cathedral, Marketplace, Temple, Totem Pole
  • Food Buildings:
    • Granary, Harbor, Supermarket
  • Infrastructural:
    • Aqueduct, Sewer System, Hydro Plant

Destroy City[]

The order to "Destroy City" allows you to massacre a city. This means slaughtering every citizen and burning every building and wonder to the ground.

  • This genocidal order gives global casus belli.
  • The command requires 2 units on the same tile. The actor unit must be non-transported and capable of capturing.
  • For foreign cities, this order is not available to Democracy nor Theocracy
    • Can only be done to cities size 2 to 8.
    • Spawns up to 5 partisans and 5 migrant refugees, and no more than a total of 8 spawned units.
  • For domestic cities, this order is only available to Despotism and Communism.
    • Can only be done to cities size 1 to 8.
    • Requires 15% or more foreign nationals in the city. In other words, only conquered or liberated domestic cities can be massacred.
    • Spawns up to 5 migrant refugees, but no partisans.


During combat, Bases may increase the defense bonus of units inside, make the units immune to Stack-Kill, and provide other bonuses and benefits.




Building a Fort requires Masonry. A Fort or Fortress can go anywhere except on a city-center or in water. It is the most primitive type of Base, but fast and easy to make, and with definitive defense bonuses and immunity to Stack-Kill which make it useful through all stages of the game.

Fortress Bases[]

Fortresses, Naval Bases, Castles, and Bunkers are all similar: they must be built on top of a Fort or Fortress, and give superior bonuses to a Fort.

  • A Fortress requires an existing Fort and Construction tech. To build one of these, move Settlers, Workers, Legions, Engineers, or Proletarians to a tile and give the order.
  • Naval Bases require an existing Fort. Naval Bases are Fortresses that may also hold ships, giving them a refuge from the open waters of the sea which have no defense bonus and risk of Stack-Kill.
  • Castles are a type of modified Fortress built on top of a Fortress. They take a significant amount of work to finish. Castles defend the same as a Fortress, but enemies cannot see units inside. Castles are immune to attacks from Siege Rams, and claim more surrounding land to your national territory.
  • Bunkers are a type of modified Fortress built on top of a Fortress. They take a significant amount of work to finish. Bunkers defend the same as a Fortress, but enemies can't see units inside. Bunkers are immune to attacks for Air and Missile units, and offer 90% resistance to nuclear detonations.

Other Bases[]

  • Airbases provide a place for aircraft to land, refuel, get repairs, and avoid stack death.
  • Hideouts can be made in Forests, Swamps, Mountains, and Jungle, but not in someone else’s territory. Units in a hideout are invisible to other players. Only Foot soldiers can make Hideouts. All Land units and Helicopters can hide in them. Other types will be seen. Hideouts are not seen or detected on the map, are invisible to anyone not occupying the tile, and only appear as an activity icon near the unit who is hiding in it. The only way to see a Hideout is to have a unit inside it. Hideouts can't co-exist with other base types. Hideouts utilize natural terrain and foliage; therefore, for each turn it is unoccupied, a Hideout has a 15% chance of being lost to weather or other forces of nature; however, Hideouts made on Ruins will never disappear. Hideouts provide no bonus of any kind except invisibility and immunity to Stack-Kill.
  • Ruins mark the site of a now uninhabited city. Units in Ruins can use the cellars, walls, and old buildings somewhat like a base. There is no defense bonus, but units in Ruins will not experience Stack-Kill.


Vigil is an order that only a limited number of units can do. The Vigil order instructs a unit to be vigilant to nearby enemy movement and auto-attack adjacent units, if the right conditions are met. 👉🏻 Only a player with shared vision can see if a unit is on Vigil.

Vigil rules and conditions[]

A unit on Vigil will attack an adjacent enemy unit if it passes all the following conditions:

  1. The enemy unit is the right type of unit that the vigil unit is watching for.
    • (Many units have restrictions on what unit types they can target under vigil. See docs on specific unit types.)
  2. The chance of losing is less than 1/6 🎲 -- that is, at least 5/6 (83 %) odds to win, OR:
    • The odds to win by attacking are better than defending AND those odds to win are better than 25%, OR:
    • The Vigil unit is set as an ALWAYS_ATTACKER (the Anti-Ballistic Missile is the only unit of this kind in MP2D.)
  3. The vigil unit is not the only unit defending a city, unless it has 90% or better odds to win (special rule not shown in chart below.)

Units don't leave vigil mode after engaging. If a unit still has moves and strength left to satisfy the above conditions, it will continue its vigil duties.

Chart: How a Vigil unit decides whether to auto-attack a unit who moves adjacent to it:



Ballistic class units[]

Catapult, Ballista, Cannon, Artillery, Howitzer, and Magnum Turret. If on Vigil, these units will do a Bombard (SUA) on qualifying enemy units who move adjacent. If the enemy is not qualifying they won't Bombard.

Ballistic units on Vigil will do Special Unit Attack on enemy military units who move adjacent if...

  • The ballistic unit qualifies to attack under the Vigil rules and conditions above.
    • 👉🏻 Standard attack odds are used to decide, but the attack itself will be a Bombardment (SUA).
  • The enemy unit is reachable by attack, and is a military (non-civilian) unit.

For ballistic class units to Vigil, they must:

  • have not moved this turn
  • be in a city or base (Fort, Fortress, etc.)
Jet fighter

Fighter type units[]

Fighter types on Vigil

A fighter can Vigil if it has not moved more than its move limit for allowing Vigil:

Fighters on Carriers can Vigil. They remain under Vigil if the Carrier moves.

Anti-Ballistic Missiles[]

ABMs on Vigil will attack only missile types: Cruise Missiles, Nuclear Missiles, Tactical Nukes. They only target and attack a single missile; all other units on the tile are unaffected. They will not vigil-attack other ABMs, as that would surely be a trap to make you waste your ABM before a Cruise Missile or nuclear missile strikes. ABMs are an "Always Attacker" when on Vigil.

More information[]

For a chart showing which units will engage which other units under these rules, see Vigil Engagement Chart.


Pearl Harbor Effect[]


PORT PENALTY in MP2 and most other rulesets is often called The Pearl Harbor Effect. If attacked in a city, defending firepower for Sea units is set to 1, and firepower of the attacker is doubled. In addition, the AEGIS Cruiser loses its anti-air abilities to prevent aircraft dropping nuclear bombs. Naval Bases or indeed, even open water, provides a safer home for navies.

City Defenses[]

There are five buildings which improve the strength of units who are attacked inside a city:

City Defense Improvements
Fortifications Fortifications

cost:35 or 45 upkeep:0

requires: Masonry

+0.33 added to Terrain Defense

(+0.50 added to Terrain Defense on Flatland) walls City Walls

cost:65 or 75 upkeep:0

requires: Construction

defense vs Land attacks*

B.coastal defense Coastal Defense

cost:65 upkeep:2


defense vs Sea attacks

Sam battery SAM Battery

cost:80 upkeep:2


defense vs Air (including Helicopters)

(not Missiles)

B.sdi defense SDI Defense

cost:140 upkeep:4


defense vs Missiles

"Nuke proof"

* Ballistic class Land units reduce the bonus: Catapult: -0.25x, Cannon, Artillery: -0.50x, Howitzer: -100% (ignores the bonus)

Note: the Great Wall wonder counts as City Walls. Gibraltar Fortress improves Coastal Defense.

Nuclear Combat[]

Nuclear missiles do not engage in combat like other units — they either strike a ground zero within range of an SDI Defense and are harmlessly destroyed, or detonate at a ground zero outside the range of SDI, which results in a blast area around the attacked tile. SDI only prevents a ground zero detonation within its range of protection, but provides no protection from blast areas after a nuclear device successfully detonated!

In addition, an Anti-Ballistic Missile on Vigil gives a chance at odds to impart an "SDI Effect" within the same radius as an SDI Defense. Of course, if the nuclear missile is adjacent, it will do its regular auto-attack before this enters into the question. Nuclear bombs have all the same rules as Nuclear missiles, with one difference. Because they are delivered by bombers, Anti-Ballistic Missiles will have no effect: instead, there are odds that the bomb delivery may be thwarted by strong anti-aircraft defenders: see the help on AEGIS Cruiser and Mobile SAM for more info.

Within the blast radius for the specific type of nuke, all units are destroyed. cities lose population, and each land tile has a 50% chance of becoming polluted with Fallout. Furthermore, the blasts will lay waste to tile improvement and infrastructure.

Number of tile improvements ON EACH TILE potentially destroyed by nuclear blast:
# tile



 Ground Zero 

 Destruction Odds 

for each
 Tile Improvement 





Atom Bomb 1 2 40% 5 cardinally adjacent
Nuclear Missile 2 4 40% 9 adjacent
Tactical Nuke 4 40% 1 ground zero
Hydrogen Bomb 3 6 50% 21 5x5 sans corners
Doomsday Bomb 3 6 60% 100 approximate

Nuclear Fallout raises the chance of Nuclear Winter — terrain begins changing into colder terrain; ice caps grow, which lowers sea levels. Workers and Engineers must be given the Clean Fallout command to dispose of nuclear waste. Fallout gradually disappears by itself -- roughly 15% will fade away each turn. However, be warned: the natural rate of dissipation is not fast enough to prevent nuclear winter, if the world has a lot of Fallout.

Diplomatic Combat[]

See this section in the page on Diplomacy.

Capturing Units[]

The following non-military units may be captured, which converts them into your own units:

  • Tribesmen, Workers, Peasants, Pilgrims, Proletarians, Migrants
  • Scout
  • Caravan, Wagon, Goods, Train, Truck, Freight

(Founders, Settlers, and Engineers can't be captured.)

To capture a unit requires a Foot soldier or Mounted unit whose raw attack value is 3 or higher. (If less than 3, the units will fight for their freedom.) Units on a tile with other units may not be captured—however, cargo Commerce units such as Goods and Freight do not count toward the number of units on the tile: commercial cargo being carried by captured units will be looted as booty and transferred to the capturer's nearest domestic city.

Units in Forts, Fortresses, or Mountains may not be captured.

Move cost to capture: 2/3 move.

In Longturn games, a unit from a nation who is idle 3 turns can't be captured unless inside the capturer's territory.

Expelling Units[]

The following non-military units can be expelled from your nation, which sends them back to their home country:

  • Settlers, Well-Digger
  • Tribesmen, Workers, Engineers, Peasants, Pilgrims, Proletarians, Migrants
  • Emissary, Diplomat, Spy
  • Caravan, Wagon, Truck
  • Scout, Airplane, AWACS

Move cost to expel: 2/3 move.

Expelling is easier than Capturing. To expel a Land unit requires any Land-based military unit except Warriors. Units on Mountains terrain may not be expelled. Units on a tile with other units may not be expelled. Expelling aeroplanes (Airplane or AWACS) requires a Fighter-type unit.

Hunting Wild Animals[]

In games which have /set animals x , with a value of x greater than zero, wild animal units will appear at game start. You will have to do combat with them.

Wild Animal hunting gives the home city of the unit who kills it a food bonus and/or gold bonus and/or culture bonus.

  • To enable wild animal units in the game, do:
    • /set animals x
      • where x is a number from 1-500 for animal frequency.
Animal Food

 for Home City 


 Furs & Ivory 

Lion 1 1
Bear 1 3
Wolf 1
Leopard 3
Tiger 3
Crocodile 2 3
 Hippopotamus  5
Rhinocerous 3 3
Polar Bear 4
Giant Squid 5 1
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