Unit and building stats

Anything without a tag comes straight from the game data. (inferred) is a guess about how the game uses that value, and (partial) is the least reliable.

Stats are <properties> attributes in the class (data\classes\<Class>.sc.xml). To change them without copying the whole class, use a patch; to create a unit, see New units.

<patch>
  <!-- Legionaries run faster: speed 60 -> 75 -->
  <set select="/class/properties[@speed]" speed="75"/>
</patch>

It goes in patches\data\classes\RHastatus.sc.xml. An attribute the class doesn't set is inherited from its parent.

Which attribute does what

Speed (speed)

• Map units per second. In the game: infantry 60-80, archers 60-160, cavalry 130-190, heroes 120, rams 40, ships 240.
• The walk animation cycle lasts step × 1000 / speed milliseconds, with step taken from the .ent.xml (Hastatus: 42 × 1000 / 60 = 700 ms). Changing only speed doesn't desync the sprite: the animation speeds up or slows down with the movement. (inferred)
• speed="0" on a unit that walks freezes the game with a division by zero. So does a class that neither defines speed nor inherits it. (inferred)

Attack rate

There's no "attack speed" attribute for units. (inferred)

• A blow lasts as long as the attack animation, the sum of the <frame duration> values in the .ent.xml, and the damage lands at the animation's action_time. Across the game's 118 animations, blows last 594 to 1584 ms, with a median of 990 ms (Hastatus: 994 ms, action_time 426).
• attack_delay is useless for units: only Catapult (500) and FakeTower (400) set it, and nothing else in the data does. (inferred)
• There are two ways to attack faster. One: shorten the attack animation's frames and rescale action_time by the same ratio. The other: Unit::SetSpeedFactor(150) from a script, which speeds up both walking and attacking by 50%. SetSpeedFactor(0) freezes the game. (inferred)
• To change the .ent.xml from a mod, an XML patch should work. A loose .ent.xml doesn't replace the game's (Custom graphics).
• Attack rate and blow timing are simulation: they must be the same for every player.

Range (range, min_range)

• Game values: infantry 15-40, archers 300-500 (ships reach 700), sentries 600, cavalry 15-40, catapults 700-800, towers 600-800. RCatapult has min_range=201.
• It's measured edge to edge: the distance between centers minus the radius of both units. That's why radius counts too. (inferred)
• A melee unit becomes ranged with range plus a projectile_class (Arrow, Javelin, Axe, Slingstone) and an attack animation with action_time.
• With range below min_range it never attacks. With range="0" on a melee unit, it doesn't either. (inferred)
• A projectile takes as long as its animation, whatever the distance (arrow 495 ms, axe and javelin 561, sling stone 300). There's no projectile speed attribute. An attacker with a projectile does half damage to buildings. (inferred)
• Catapults: the arc comes from shot_tan and shot_height. Don't change them on one computer only.

Hitbox and size

Always set radius on a new building. The inherited one (Building: 600) is huge, and attackers "reach" the building from very far away. Real buildings use 160-250 for barracks, 47 for towers, 80-110 for walls and 333-345 for outposts.

Damage and armor

Constants from data\const.ini, section [GamePlay]: MinDamage=3, MinPercentOfAttackersDamage=20, DamageAmplify=200 and LevelDifferenceDamageTable. How they're used is (inferred):

• A blow does damage − armor_slash of the defender, with a floor of 20% of the attacker's damage and never less than 3. Then the level difference between the two is applied: it runs from −90% to +90%, and if the defender has the higher level, it subtracts.
• armor_pierce isn't part of the calculation: you can write it and it does nothing (partial: a script may use it). To give armor, use armor_slash.
• damage_type (slash, pierce, siege, none) doesn't change the damage: it decides what the unit can attack. slash and pierce attack units (and buildings if there's a projectile), siege attacks buildings too, none doesn't attack.
• Buildings have no armor: the damage goes in whole.
• DamageAmplify is the damage to a building's garrison. Tweak these constants with INI patches.

Other attributes

What does nothing

armor_pierce (partial), speed_modify and taunt (as a property it's a sound name) are read and never used. (inferred) attack_delay is useless on units. target_priority only matters for towers and catapults; for units, use target_factor.

Changing things mid-game (from a script)

The functions are listed in funciones-del-juego.txt. To change the damage of a single blow, use the OnAttackResolved event with Mod_SetAttackDamage (Unit specials).

What XML can't do

• The combat formula (flat armor, floors, level table). You can only adjust the const.ini constants.
• Projectile speed and flight range: the blow lands if the distance is below range + 150. (inferred)
• New code behaviors: the cpp_class values are only the ones the game ships with.
• Formation logic, beyond what Formations allows.

Multiplayer

Almost everything above is simulation. Every player must have the same mod, and the game checks this when entering a lobby; a difference between two players desyncs the game and it's aborted. Cosmetic: selection_radius, healthbar_*, icon, display_name, help and the sprites.

Sprites (.rle) aren't part of the check. The full list of what is checked is in the README.

What we don't know

• The exact conversion between map units and screen pixels.
• Whether sight also limits how far a unit looks for targets. It reveals the fog and scripts use it to search, but the exact calculation is unknown.
• Which formation_priority goes in front in a formation.
• What happens with an action_time longer than the animation. Avoid it.