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Tough A.I. 2

Toughens the AI by increasing their Combat Strength bonuses.

  1. Trigan Emperor

    Want the AI to give you a greater challenge in warfare? Then this is the mod for you!


    This mod toughens the AI by increasing their Combat Strength bonuses.


    The AI, in Civ VI, finds it hard to compete with the human player when it comes to tactical thinking on the battlefield, which means that wars against the AI tend to be one-sided.

    The Civ VI game code governing AI tactical behaviour on the field of battle is, unfortunately, not available for modification, so it can't be improved by the playing community. This means that, in order to make the AI more challenging to the human player, the quantity of its units must be increased, which the game does by giving Production bonuses, or its quality must be increased, by making AI units stronger and tougher.

    The vanilla game does already give the AI an increasing level of Combat Strength bonuses as game difficulty progresses - each difficulty level above Prince gives the AI +1 Combat Strength in battle. So on the highest difficulty level, Deity, the AI gets +4 Combat Strength.

    However, this is quite a minor increase in difficulty. For comparison, here are some other Combat Strength bonuses that are given in the game:

    +5 = Combat bonus provided by a Great General
    +5 = Bonus provided by Defender of the Faith Belief near friendly cities that follow your religion
    +7 = Tier I melee unit promotion vs. melee and ranged units
    +10 = Difference between regular unit and Corps
    +10 = Tier I melee unit promotion when defending against ranged attacks
    +10 = Bonus provided by Crusade Belief near foreign cities that follow your religion
    +17 = Difference between regular unit and Army

    So what this mod does is increase the Combat Strength bonus that the AI receives in battle at higher game difficulty levels. This means that AI units will take less damage from the human player, and inflict greater damage upon the human player.

    The default Combat Strength bonuses as set in this mod for each difficulty level are as follows, along with the values given in the vanilla game for comparison:

    Prince: +0 (Vanilla game: +0)
    King: +5 (Vanilla game: +1)
    Emperor: +10 (Vanilla game: +2)
    Immortal: +15 (Vanilla game: +3)
    Deity +20: (Vanilla game: +4)

    While the Combat Bonuses the AI receives with this mod at higher difficulty levels may appear daunting, the game offers many ways to increase one's own Civilization's Combat Strength bonuses and narrow the gap with the AI. These include different Governments, Beliefs, Governors, Policy Cards, Great Generals, diplomatic visibility levels and many more. (See further down the page for a more comprehensive list.)

    Success in warfare on the highest difficulties in this mod is therefore as much about decisions made, and actions taken, to improve one's Civilization's Combat Strength bonuses as it is about tactics on the battlefield.


    - The Combat Strength bonuses in this mod are given to AI civilizations, city-states and barbarians. (In the vanilla game, Combat Strength bonuses are only given to AI civilizations). So the human player will be at a disadvantage in combat against all AI. AI vs AI combat is not affected. When a human player levies a vassal city-state and takes control of their units, they will no longer receive the AI combat bonuses.

    - The AI will get the specified Combat Strength bonus in religious/theological combat as well as military combat. There are various ways in the game to improve one's own Combat Strength bonus in theological combat, but if one is finding it tough countering proselytizing AI religious units, then one can always declare war and put the heretics to the sword with one's military units.

    - The rate of XP gain from combat has been changed to make it slower to gain promotions. This is to compensate for the fact that tougher AI means more fighting, and therefore more opportunities to gain XP.


    Here's a list of things that affect Combat Strength in the game:

    - Unit Combat Strength

    - Unit Class modifiers (such as Anti-Cavalry vs Cavalry, Melee vs Anti-Cavalry)

    - Unit Promotions

    - Terrain modifiers (including Amphibious/River penalties)

    - Fortification modifier (for not moving unit in previous turns)

    - Support/Flanking bonuses

    - Damaged unit penalty

    - Insufficient strategic resource penalty

    - Embarked penalty ('Adjusted base strength when embarked')

    - Leader Abilities, including those of Frederick Barbarossa, Genghis Khan, Hojo Tokimune, Matthias Corvinus, Montezuma, Phillip II, Shaka, Teddy Roosevelt, Tomyris

    - Great General/Admiral

    - Governor Victor (and Ibrahim for the Ottomans)

    - Policy cards, such as Discipline, Bastions, Wars of Religion, National Identity, Their Finest Hour

    - Governments, such as Oligarchy, Communism and Fascism

    - Diplomatic Visibility ('Intel on enemy movements', +3 Combat Strength per level of difference)

    - Beliefs, such as Defender of the Faith and Crusade

    - Military Alliance (+5 Combat Strength against units of players at war with you and your ally)

    - Corps (+10) and Armies (+17)

    - World Congress resolution (to certain religion or types of military unit)

    - Game difficulty

    Changing the mod's default AI Combat Strength settings

    If so desired, the mod's AI Combat Strength bonus values can be adjusted to one's own preference, by editing the mod's Tough_AI.XML file.

    Increasing AI Combat Strength bonus from game difficulty follows a scale created by two numbers. Under HIGH_DIFFICULTY_COMBAT_SCALING in the XML file, one will see two entries. The first, called 'Value', is the starting point of the scale, while the second, called 'Extra', is the increase in AI Combat Strength per difficulty level from Prince difficulty level and above. In the vanilla game, 'Value' is set at -1, and 'Extra' is set at 1, while this mod changes these numbers to -5 and 5 respectively. Since, by default, the 'Value' is a negative version of the 'Extra' number, they will cancel each other out at Prince difficulty, giving AI Combat Strength bonus of +0 at that difficulty level.

    By changing these two numbers, one can arrive at any AI Combat Strength bonus one desires for any given game difficulty level. The simplest way to specify a particular AI Combat Strength bonus for a game is to turn off the scaling by changing the 'Extra' to 0. Then change the 'Value' number to whatever you want the AI Combat Strength bonus to be. The specified Combat Strength will be used in any game difficulty you choose from Prince to Deity.

    It is recommended to also change the rate of XP gain, by editing the Value and Extra numbers under HIGH_DIFFICULTY_UNIT_XP_SCALING in the Tough_AI.XML file. As with editing HIGH_DIFFICULTY_COMBAT_SCALING, set Extra to 0 and set Value to, by my recommendation, three times greater than the Combat Strength as a negative value, e.g. If +10 Combat Strength, set XP Value to -30.

    The 'Cheat Menu For Units' mod is useful for trying out settings in-game.


    Works with the base game as well as with expansions. No known compatibility issues with other mods, although there may be if they modify HIGH_DIFFICULTY_COMBAT_SCALING or HIGH_DIFFICULTY_UNIT_XP_SCALING. So search the mod in question for those term if unsure.


    Thanks to LeeS for coding assistance and his Modding Guide.

    [This mod can be found on Steam Workshop here.]
    glider1 likes this.

Recent Updates

  1. XP gain adjusted