Horn of the Abyss (HotA) carefully adds many innovations: new factions - the pirate "Cove" and Factory, new creatures, a series of new artifacts and other game world objects, as well as new campaigns and maps.

The expansion's storyline develops parallel to the events of Armageddon's Blade and fits into the setting of the original Heroes III. The developers plan a trilogy of campaigns centered around the Horn of the Abyss artifact.

HotA includes 5 new campaigns and 55 single scenarios. Maps have a separate format and editor supporting all innovations. The random map generator has been reworked: when creating maps without water, all aquatic elements are excluded. New map sizes: H (Huge), XH (Extra Huge), G (Giant).

Gameplay, Graphics and Interface

One innovation is negative luck: now units deal less damage with negative values. The luck parameter applies even to armies without a hero. For ranged units like liches and magogs, targeted shooting has been introduced, allowing selection of the attack zone.

On the adventure map, creature dwelling populations no longer reset weekly but continue to grow like in town buildings. Creature parameters have been revised, prices in altars, markets, and artifact merchants changed, vault guards reworked, and necromancy skill effectiveness reduced. In individual towns, building conditions and costs have been modified. For example, in Conflux, the Pyre was added, increasing the growth of level 7 creatures (firebirds and phoenixes).

Developers paid attention to graphics and interface: minor errors in town screens and game menus were fixed, fonts improved for localized versions. The battle screen became fully animated, animations of several creatures and some spells updated. Battle backgrounds now depend on terrain: for example, on volcanic maps underground, lava caves are visible.

The hero's route color on the map is supplemented with a burgundy shade showing cells that are inaccessible even with full movement points. Town appearance now changes depending on fortification level, and some creatures have updated visual styles.

New Factions

Cove

Cove is a full-fledged faction added in HotA; it's a pirate/naval power with strong ranged capabilities and maritime theme. It also has specific objects and mechanics, like cannons. Cove is especially strong on water maps thanks to sea control and bonuses for maritime activity.

Strengths:

• Very strong in ranged combat and combat units effective on water

• Excellent mobility and map control with lots of water

• Strong high-level units (Sea Serpent / Haspid)

Weaknesses:

• On maps without water, advantages are noticeably reduced

• Low-level units in some squads aren't as strong as in classic factions - requires skillful micro and economic development

Factory

Factory created with wasteland and mechanization themes. It's divided into two conditional branches - "natural": harsh living creatures inhabiting lifeless lands, and "mechanical": retro-machines, homemade constructions. The faction has two strong level 7 units (mechanical and living variants), providing flexibility in army composition and tactical shifts from aggressive early game to powerful late game.

Natural Branch (living creatures):

Includes Halflings, Armadillos, Sandworms, Couatls, suitable for aggressive early game, quick raids and capturing objects. Good for players preferring mobility and durable troops.

Features:

• Healed and resurrected by normal magic like any living units

• Have classic combat roles - reconnaissance, mobile attacks, tactical abilities

• Some possess unique mechanics: Sand worms consume corpses to immediately make an additional attack during the same round; Couatls are very fast flying units with powerful strikes

• Usually faster than mechanical units

Mechanical Branch (mechanical creatures):

Includes Mechanics, Automatons, Gunslingers/Bounty Hunters, Dreadnoughts/Juggernauts, making the faction strong in prolonged battles and late game. Suitable for players who love powerful, albeit slow units capable of direct, powerful assault on opponents and breaking through defenses head-on.

Features:

• Cannot be healed or revived by normal restoration magic

• Can be repaired by engineers - Factory's key mechanic

• Have abilities that living units lack: Automatons can explode dealing area damage; Gunslingers have preemptive shot; Dreadnoughts are heavy combat machinery with large durability

• Usually slow but much more durable and predictable

Strengths:

• High tactical flexibility thanks to two creature groups and two level 7 units

• Many unique abilities and synergies with skillful unit mixing

Weaknesses:

• Town and mechanical branch development can be resource-intensive - requires investment

• Some units are slow; faction requires strategic planning and understanding of synergies

Heroes and Creatures

The Scouting skill has been strengthened for heroes, revealing more territory. Two heroes with "Navigation" specialty (Sylvia and Voy) were replaced with Beatrice and Kinkeria for maps without water. Heroes from official expansions that caused imbalance were replaced with original ones again.

Besides Cove and Factory units, HotA added four new neutral creatures: satyr, leprechaun, steel golem, and the Cthulhu-like fangarm, summoned through the Horn of the Abyss.

Game World

HotA adds many new gameplay and decorative objects. For example, the Cannon Yard allows heroes to obtain cannons - a war machine of the new Cove town that replaces the ballista and is enhanced by the "Artillery" skill. Warehouses were introduced, providing a specific resource weekly, and creature vaults expanded where heroes fight for resources, artifacts and warriors.

Many old objects were reworked for new landscapes - ice gates, underground structures, water terrain objects. New landscapes affecting gameplay were added to existing ones.

HotA added 22 new artifacts (including 4 combination artifacts). Items with unique effects appeared: artifacts reducing enemy morale and luck, Boots of the Wanderer for movement without penalties across rough terrain, Ring of Oblivion making losses permanent. Combination artifacts unite old items with additional properties, for example, the Diplomat's Cloak allows fleeing and surrendering in defense or neutral battles. The Golden Goose is taken from Heroes II, and the Horn of the Abyss is the key artifact of HotA's storyline.

Conclusion

Horn of the Abyss can rightfully be called Heroes of Might and Magic 3.5. This is exemplary fan work that can revive interest in the 1999 game not only for veterans but also newcomers, thanks to making the game comfortable for modern players while preserving that beloved gameplay and atmosphere.