Each character has a unique skill tree accessible from the pause menu. Skills are unlocked using experience points gained from defeating zombies, completing missions, and substories. The skill tree is divided into categories like 'Body' (health, defense), 'Mind' (Heat Gauge, stamina), and 'Technique' (weapon-specific abilities, melee attacks). Prioritize upgrades that complement your chosen character's playstyle. For example, Kiryu benefits from 'Body' and 'Technique' upgrades for his shotgun, while Majima thrives with 'Mind' and 'Technique' for his submachine gun. unlock 'Ultimate Heat Actions' as soon as they become available, as they are incredibly powerful. Regularly check your skill tree and invest your experience points wisely to keep your character competitive against the escalating zombie threat.
