Charge Bonus

Charge Bonus is a stat on the unit card. It is a short boost of offensive power.

Overview
A Swordsmen unit has 32 melee attack and 14 Charge bonus. When the unit is normally in combat its melee attack is 32. However, when the unit charges, it gains the 14 charge bonus as a boost to their melee attack. This lasts over 10-15 seconds and fades over time. As such charge bonuses are highest and most useful on units like shock cavalry that can charge in and out of a unit quickly, renewing their charge bonus each time. It is notable that charging takes up a significant amount of Fatigue which should be kept in mind.

In-game description
"This increases a unit's melee attack and damage when charging."

Charge Defence
Many spearmen and halberd units have charge defence against large units. This nullifies the charge bonus of a charging enemy when the spearmen are braced (standing still) and charged from the front. When the two units make contact, you may see the braced troops still get knocked over, however they take little to no damage. Being charged from the side or behind will not negate the charge bonus, and the charged unit will take full damage.

Other units have charge defence against all or Expert charge defence, which does the same thing but to all types of units regardless of entity size. This means that if they are charged from the front while braced by any unit, they will negate their charge.

Strategy
When trying to charge an enemy with charge defence and you cannot get around to their flanks, consider this strategy. Charge a disposable unit or a single entity unit like a fast lord or hero into the front of the enemy. Their charge bonus will be negated, but the spearmen will no longer be brace because they are fighting your unit. Then charge in with your shock cavalry, so they can do full damage. This is a risky and somewhat niche strategy, however not one without its merits.