The spell system is revamped with a spell point counter replacing the memorisation model of the original: the Knowledge primary skill now determines a hero's maximum spell point pool, with one point of Knowledge equating to ten spell points. This system was taken further in Heroes III, in which every non-neutral unit receives an upgraded incarnation. The game introduces upgrades to the series - with the necessary structures built or adventure map locations visited, certain units can be upgraded, entailing attribute boosts and new abilities.
The combat battlefield is enlarged and creature sizes reduced. Individual heroes can obtain a maximum of eight secondary skills.
Hero development is enhanced with secondary skills, replacing the inherent class bonuses of the prequel fourteen skills are available, with three tiers of expertise which can be achieved upon level-up: Basic, Advanced and Expert. While closely similar in design to the first game, Heroes II overhauls some gameplay elements.
