Charge

Charge is a core keyword that denotes that a unit is capable of charging or rushing a defender, in which case the defender's Willpower decreases. This keyword is mostly seen on creatures like horses, bulls, rams, etc.

Card Text
Units defending against [card name] get -X Willpower equal to [card name's] Loyalty.

Usage in Decks
Cards with Charge can be found in any color of deck.

Examples
Glen's unit attacks Linda. Glen's unit has 3 Loyalty and Charge. Linda defends with a unit that has 4 Willpower. Because of the Charge effect, Linda's unit loses 3 Willpower, taking it down to 1.