Combat

“In war, the moral is to the physical as three to one.”

Combat in Annhexation is resolved through a deterministic formula that weighs attack and defence strength, modified by terrain, fortifications, promotions, civilisation bonuses, and unit health. Understanding these mechanics is essential for winning battles efficiently and minimising losses.

Attack Types

There are two fundamental attack types:

Melee Attack (Range 0)

Melee units – Warriors, Swordsmen, Horsemen, Knights, Tanks, and others with range 0 – must be adjacent to their target to attack. After a successful melee attack that destroys the defender, the attacker advances into the defender’s hex.

Both attacker and defender take damage in melee combat. The attacker deals damage based on attack strength; the defender retaliates based on defence strength.

Ranged Attack (Range 1+)

Ranged units – Archers, Catapults, Longbowmen, Cannons, Artillery, and Frigates/Destroyers/Battleships – can attack targets within their range without being adjacent. Ranged attackers deal damage but take no retaliation damage from melee defenders. However, if both attacker and defender are ranged units, both take damage.

Combat Requirements

To initiate an attack, a unit must:

• Have movement points remaining (at least 1 internal point).
• Not have exceeded its attack limit for the turn (1 attack normally, 2 with the Blitz promotion).
• Be at war with the target’s owner.
• Be within range of the target (adjacent for melee, within stated range for ranged).
• For melee attacks, be able to enter the target’s tile (terrain must be passable, territory rules must allow entry).

After attacking, a unit’s movement is set to 0 unless it has the Blitz promotion and attacks remaining.

The Combat Formula

Combat damage is calculated as follows:

1. Compute attack strength: Base attack stat x (attacker HP / 100) x modifiers.
2. Compute defence strength: Base defence stat x (defender HP / 100) x modifiers.
3. Calculate ratio: ratio = attack strength / (attack strength + defence strength).
4. Damage to defender: Round(ratio x 50).
5. Damage to attacker: Round((1 - ratio) x 50) for melee; 0 for ranged vs melee.

A ratio of 0.5 (equal strengths) deals 25 damage to each side. Higher ratios favour the attacker.

Unit Health

All units have 100 HP. Damage reduces health; at 0 HP the unit is destroyed. Damaged units fight at reduced effectiveness – a unit at 50 HP has its combat strength halved. Heal damaged units by keeping them stationary (they recover HP each turn) or by the March promotion (healing while moving).

Defence Bonuses

Terrain Defence

City Defence

A unit defending in a city with Walls and the Great Wall receives +200% defence – tripling its effective defence strength.

Garrison and Fortification

These are mutually exclusive. A unit in a city gets the garrison bonus automatically regardless of its fortification status. Outside a city, the fortify action provides the same +25%.

Attack Penalties

River Crossing

Melee attackers crossing a river to attack suffer a -25% attack penalty. This is a multiplicative modifier applied to the attacker’s effective strength. Combined with the defender’s terrain bonus, a river crossing attack can be extremely costly.

Pillage Exposure

A unit that pillaged an improvement on its current turn defends at half strength until the start of its owner’s next turn. Exploit this vulnerability by attacking enemies immediately after they pillage your tiles.

Combat Modifiers

Promotions

Promotion bonuses stack multiplicatively with other modifiers.

Siege Bonus

Siege units – Catapult, Cannon, and Artillery – inherently deal +50% damage against units defending in cities. The Siege promotion provides an additional +50% that stacks with the inherent bonus. A Cannon with the Siege promotion deals +100% vs city defenders.

Civilisation Bonuses

Unit Type Bonuses

Some units receive attack bonuses against specific enemy types:

Declaring War

You must be at war with another civilisation to attack their units. To declare war:

• You must have researched the Currency technology (which unlocks diplomacy actions).
• Your government must not be Democracy (democracies cannot declare war – you must change government first).
• You do not need to be adjacent to the enemy or have met them previously; declaring war is a diplomatic action.

Barbarians are always at war with everyone. You never need to declare war on barbarians.

Capturing Cities

When a melee unit destroys the last defender in an enemy city, it advances onto the city tile. You then have the option to capture the city:

• The city’s population is reduced by 1 (minimum 1).
• The city enters resistance for 5 turns. During resistance, the city produces at half its normal rate unless a military unit is garrisoned inside.
• Some buildings may be destroyed during capture.
• The city transfers to your control, including its tile improvements and territory.

Only melee units (range 0) can capture cities. Ranged units can bombard city defenders but cannot take the city itself.

Barbarians

Barbarians are hostile NPCs that spawn from village encounters and wander the map. They:

• Are always at war with every civilisation.
• Pillage improvements and cities in their path.
• Cannot be negotiated with.
• Provide experience for your units when defeated.

Early in the game, barbarians are a genuine threat. Keep a garrison in your cities and deal with barbarian warriors before they damage your infrastructure.

Nuclear Weapons

The most destructive weapons in the game, nuclear missiles require the Manhattan Project wonder and Nuclear Fission technology. A nuclear strike:

• Has a range of 10 hexes from the launching city.
• Halves the target city’s population (minimum 1).
• Destroys 4–8 buildings in the target city (randomly selected from all buildings and wonders).
• Deals 50 HP damage to all units on adjacent hexes.
• Destroys any unit on the target hex outright.
• Destroys all improvements and roads on adjacent hexes.
• Triggers war with all civilisations (unless already at war with the territory owner), blocked from peace for 20 turns.

Nuclear weapons are a last resort. Using them will turn every civilisation against you, but the devastation they cause can be decisive in a losing war.

Experience and Levelling

Units gain experience through combat:

The maximum experience is capped at 30 XP. Promotions are earned at experience thresholds:

Strategic Tips

1. Never attack across a river if you can avoid it. The -25% penalty is devastating. Manoeuvre to cross the river first, then attack from the same side.

2. Use ranged units behind melee lines. Ranged units take no retaliation damage from melee defenders. Position Archers and Catapults behind your front-line Warriors and Swordsmen.

3. Siege units are essential for city assaults. The +50% bonus against city defenders (doubled with the Siege promotion) makes Catapults and Cannons far more effective than melee units against fortified cities.

4. Concentrate fire. A damaged unit fights at reduced strength. Focus multiple units on a single defender to destroy it quickly rather than spreading damage across several enemies.

5. Terrain is your ally on defence. Place defenders on hills, in forests, or behind rivers. A Spearman fortified on a forested hill in a city with Walls is nearly impossible to dislodge.

6. Health management matters. A unit at 50% health has half its combat effectiveness. Pull damaged units back and let fresh troops take the front line.

7. Blitz promotion is transformative. A Knight or Tank with Blitz can attack twice per turn, making it the most dangerous offensive promotion in the game.