War Guide

To take a city in Civilization 4, bring one stack that holds both siege and attackers: bombard the city's defenses with Catapults (later Trebuchets, Cannons or Artillery) until they reach zero, attack first with the siege units so their collateral damage wounds several defenders at once, then finish the weakened garrison with melee or armored units promoted with City Raider (+20%, +25% and +30% city attack at its three levels). To defend, do the reverse: archery or gunpowder units with City Garrison, fortified in cities on hills and behind walls, plus your own siege to break an enemy stack before it arrives. That is the design Soren Johnson describes in the manual: one Strength value per unit, counters for every unit, and siege as the counter to stacking itself. This guide covers combat, sieges, promotions, defense, the armies of each age, war weariness, Great Generals, vassals, and war at sea and in the air.

Quick facts

Source: Civilization IV manual, pp. 40-50, 136-145; Civilization IV: Warlords manual, reference charts pp. 129-135.

How combat works

Every unit has one Strength value, used for both attack and defense, changed by terrain, fortification, promotions and bonuses against other unit types. Equal modified strengths mean even odds; double the strength means 2 to 1 (p. 40). Johnson wrote that merging attack and defense, with situational bonuses such as archers defending cities and hills and spearmen against horses, was meant to encourage combined arms; GameSpot's 2005 review noted that it ends the old "tribal spearman defeating a tank" upsets. Hover an attack to see the exact odds before you commit. The rules are on Combat.

When you attack a stack, its defender with the best odds fights, and you cannot enter the tile until every defender is dead (pp. 41-42). Most units attack once a turn (Blitz allows more), while a defender can fight any number of attacks. Mounted units may withdraw from a losing attack against non-mounted units. Units heal fastest inside your own borders and slowest in enemy land.

The stack and its counter

Johnson named the problem himself in the manual's designer notes (p. 182): if every unit has a counter, the best play is the "Stack-of-Doom (SoD)", one giant stack, because its best defender always fights. His answer was collateral damage: Catapults, Cannons and Artillery are "stack-killers" that counter a style of play rather than a unit (pp. 182-183). When a siege unit attacks, it also damages several other units in the defending stack.

That makes the attacker's stack and the defender's stack the same shape: siege to wound, strong units to finish, defenders to protect the siege. Beyond the Sword tuned it: siege units have a maximum damage limit and cannot attack units already below it, and some mounted units and helicopters deal flanking damage to siege units in a stack even when they withdraw (p. 24). Drill II, III and IV each give 20% protection from collateral damage under the patched rules. Every unit is on Units.

Taking a city, step by step

1. Bombard. Catapults and later siege units and ships lower a city's defense bonus each turn; bombarding always succeeds and never hurts the units inside (p. 42). The Warlords charts give each unit's rate: Catapult 15% a turn, Cannon 20%, Trebuchet and Artillery 25%.
2. Attack with siege first. GameSpot's guide (Doug Radcliffe, Jan 18, 2006): once defenses are at 0%, the siege unit "should attack defending units. It'll likely perish but the collateral damage inflicted will provide a boost to your remaining attackers." A Catapult has a 25% chance to withdraw.
3. Finish with City Raiders. Melee, siege and armored units can take City Raider; the Swordsman also has +10% attacking cities, and the Warlords Trebuchet +100% against units in cities.
4. Decide the city's fate. You may keep or raze it; a size-1 city or one with no culture is razed automatically. A kept city resists for some turns, producing nothing, and loses all its culture; a Great Artist's Great Work ends resistance at once. You keep its world wonders, but national wonders in it are destroyed.

GameSpot's guide suggests razing a city that is far from your others and hard to hold, since a kept city brings resistance and maintenance, and adds that pillaging improvements "will be just as damaging" to a rival as beating its units. Avoid close fights: soften the stack first, because "the defender utilizes its best defender".

Promotions for attack and defense

Experience comes from combat: the first promotion at 2 XP, then 5, 10, 17 and so on, and attacking earns twice the XP of defending. New units start with XP from Barracks (+3 after patch 1.61), Vassalage (+2) and Theocracy (+2, in state religion cities), and these add up; West Point gives +4 and the Pentagon +2. Aggressive leaders get a free Combat I for melee and gunpowder units.

Source: Civilization IV manual, pp. 136-145.

GameSpot's guide advises specializing each unit for its job (City Raider for attackers, city defense for garrisons, Woodsman in forests) rather than stacking raw Combat, and watching which units your enemy builds. Johnson's own example (p. 183) is a City Raider swordsman becoming a "city-killer" and a Medic pikeman healing its stack. All promotions are on Promotions.

Defending your cities

Archery units are built to defend: an Archer gets +50% in cities and +25% on hills, and the Longbowman (strength 6, Feudalism) +25% in both. Hills give +25% defense and forests and jungles +50%; attackers crossing a river are weakened; fortifying adds up to +25%. Walls and Castles each give +50% against pre-gunpowder units, but Musketmen and later units get no benefit from them, only from culture, and the two city bonuses do not stack: the higher applies (p. 49). Each culture level adds 20% defense.

Protective leaders give archery and gunpowder units free City Garrison I and Drill I, and the Chichen Itza wonder gives +25% defense in every city. Keep siege of your own at home: a stack parked outside your city is exposed to your Catapults' collateral damage just as yours is to theirs.

Armies through the ages

Source: Civilization IV: Warlords manual, reference charts pp. 119-128; Beyond the Sword manual, pp. 25-26. Numbers are Strength.

Beyond the Sword added the Cuirassier, Anti-Tank Infantry, Mobile Artillery and Paratroopers, without printing their stats in its manual (the in-game Civilopedia has them). Strategic resources gate many units (Copper or Iron, Horses, Oil, Aluminum), and Johnson wrote that the map generator keeps two Iron sources at least seven tiles apart to spread them fairly.

War weariness and the home front

A long war makes your people unhappy. The manual (p. 51) notes that cities with many citizens of the enemy's nationality suffer more war weariness. Police State (Fascism) gives +25% military production and -50% war weariness; Mount Rushmore cuts war unhappiness by 25%; Hereditary Rule gives +1 happiness per military unit in a city. GameSpot's guide pairs Police State with the Heroic Epic (+100% military unit production in its city) for a long war. Units also cost upkeep that grows with empire size, shown on the Financial Advisor (F2).

Great Generals (Warlords)

Since Warlords, combat XP fills a track on the Military Advisor (F5) that produces Great Generals, each costing more than the last (pp. 10-11). A General can join a unit as a Warlord (20 XP shared among the units on its tile, free upgrades and Warlord-only promotions such as Combat VI and Leadership), settle as a Great Military Instructor (+2 XP for new units in that city), or build a Military Academy (+25% military production). Imperialistic leaders earn them twice as fast, the Great Wall doubles points from battles inside your borders, and Beyond the Sword raised the threshold.

Vassals, peace and allies

Warlords added vassal states. A civilization that capitulates in war becomes your vassal: it follows you into your wars, cannot declare war or peace by itself, and can only break free if it grows past half your size or loses half its land (pp. 12-13). For victory and score you count half of a vassal's land and population, but vassals raise your own city maintenance. GameSpot's Warlords review summed it up: "you can subjugate a foe and make them your devoted ally." Peace treaties last at least 10 turns, and Defensive Pacts pull partners into your wars; see Diplomacy.

War at sea and in the air

Ships carry and bombard. Land units attacking from boats fight at -50% strength unless they have Amphibious; a Galleon carries 3 units, a Transport 4; Frigates and later warships bombard city defenses, and the Battleship (strength 40) also deals collateral damage. A Drydock builds ships 50% faster and gives them extra XP. Beyond the Sword lets ships blockade and plunder enemy trade routes.

Aircraft strike, scout and intercept within their range from your cities and Carriers (3 Fighters each). In Beyond the Sword a city holds 4 air units, 8 with an Airport, Forts can be built outside your borders and house ships and aircraft, and, as GameSpot's preview put it, Paratroopers can drop on any square. Nuclear weapons need the Manhattan Project; a nuke hits its target and the eight surrounding tiles, Bomb Shelters cut the damage by 75%, and using one brings heavy diplomatic penalties.

Winning by war

Two victories come from war: Conquest, eliminating every rival (a civilization dies with its last city), and Domination, controlling two-thirds of the land and 25% more population than any rival (p. 106). The Victory screen (F8) tracks both; the rules are on Victory Conditions.

Frequently asked questions

How do you take cities in Civ 4? Bring siege units with your Civilization 4 attack stack, bombard the city's defenses to zero, attack first with the siege units for collateral damage, then finish the wounded defenders with City Raider units. GameSpot's 2006 guide gives the same order.

What beats a stack of doom in Civ 4? Siege units: Soren Johnson designed Civilization 4's Catapults, Cannons and Artillery as "stack-killers" whose collateral damage wounds several units in a stack with each attack. Drill promotions give some protection from it.

What are the best defenders in Civ 4? In Civilization 4, archery units defend best early (an Archer gets +50% in cities and +25% on hills), then Longbowmen, Musketmen, Riflemen and Infantry. Give them City Garrison, fortify them, and use hills and walls, remembering that walls do not help gunpowder defenders.

How do I reduce war weariness in Civ 4? Civilization 4's Police State civic cuts war weariness by 50%, Mount Rushmore cuts war unhappiness by 25%, and Hereditary Rule makes each military unit in a city a source of happiness. Fighting a civilization whose nationals live in your cities makes weariness worse.

What do Great Generals do in Civ 4? In Civilization 4 since Warlords, a Great General can lead a unit as a Warlord (sharing 20 XP and unlocking special promotions), settle as a Military Instructor (+2 XP for new units in that city) or build a Military Academy (+25% military production). They come from combat experience.

How do you win a domination victory in Civ 4? Control two-thirds of the world's land and have 25% more population than any rival; a Civilization 4 vassal's land and population count half for you. Conquest victory instead needs every rival eliminated.

Sources

• Sid Meier's Civilization IV manual, 2K Games and Firaxis Games, 2005 (read Oct 21, 2026)
• Civilization IV: Warlords manual, 2K Games and Firaxis Games, 2006 (read Oct 21, 2026)
• Civilization IV: Beyond the Sword manual, 2K Games and Firaxis Games, 2007 (read Oct 21, 2026)
• Civilization IV Walkthrough, GameSpot (Doug Radcliffe), Jan 18, 2006
• Civilization IV Review, GameSpot (Andrew Park), Oct 26, 2005
• Civilization IV: Warlords Review, GameSpot (Jason Ocampo), Jul 25, 2006
• Civilization IV: Beyond the Sword Impressions: First Look, New Factions, Espionage, End Game, GameSpot, May 25, 2007
• Analysis: Soren Johnson On Playing The Odds, Game Developer, Mar 16, 2010