Water War - Submerged was one of the earliest maps to do something different. The game consists of two warring factions of amphibious creatures, Clan Aqua and Clan Marine, battling it out across the ocean between their island encampments.
The factions are completely identical, right down to the unit models and colours. The game is a 4v4 matchup over three lanes, but this is about as non-standard as three lanes gets!
What makes Water War interesting is its strikingly original approach to terrain design: the game takes place on both the ocean's surface, and directly below on the seabed. The two terrains exist in parallel: by using the submerge/surface ability innate to every hero, it's possible to immediately vanish, and reappear at the same position on the other terrain.
Both line-of-sight and the minimap only reveal what's happening on your current plane, making map awareness a much more complicated and nuanced affair. It increases the demand for teamwork and communication, as players try to cover each-other's blind spots, and keep tabs on enemy whereabouts. There are also implications for lane-control, as two of the lanes overlap above and below the water.
While the side-lane troops swim directly towards the enemy base along the surface, troops on the middle lane walk out of the base, and immediately descend to the seabed to continue marching along the ocean floor. The waves (haha) only spawn every 60 seconds, which leaves a lot of time for stragglers to beat on towers uncontested.
Due to inheriting Warcraft's default damage and armour types, the fact that towers happen to deal piercing damage makes them particularly ineffective against heroes. Heroes deal poor damage to structures as well, but it's all too possible to simply tank towers while your troops deal most of the damage. Combine this with being able to submerge instantly away from danger, and tower diving becomes almost routine.
There are a separate set of towers on each plane. The seabed has a higher concentration of them, creating a zone of safety for friendly heroes, and is also harder to push against since there are four towers but only one lane's worth of troops. Taking out towers at one water level makes it a bit easier to siege towers on the other, since heroes can more safely switch plane to escape trouble.
The available items are mostly limited to a small subset of the usual Warcraft items, and offer nothing remarkable. The presence of a "secret shop" located somewhere around the map is no surprise, and here the Magic Merchant sells the standard Warcraft orb items, along with an item that can reveal an area of the map for a short time (but only on your current plane).
Scattered around the islands and sea bed are various jungle camps and single-use powerups like seaweed for healing, and mana stones for mana. Some of the jungle camps drop special book items which allow the owner to cast a specific spell, though plenty of other items are available as item drops. The two largest islands have spiralling jungles, terminating in a more powerful camp which drops a special item on death.
A practical concern is that all of the powerup locations and item drops are pre-allocated to specific creeps, which means that after playing the map a few times, players will learn to race for all best drops and the free gold coins lying around, inflating their net worth and messing up the flow of the game.
This was likely an unintended consequence of adding flavour to the map without much concern for serious play - the map was made for fun after all.
Another interesting quirk is the hero creation process. Instead of picking an existing design, players piece together their own hero by answering a series of questions:
- Would you like to be ranged, or melee and get +30 damage, +2 armour, and +20 movement speed?
- What primary attribute would you like (agility, intelligence, or strength)?
- What colour hero would you like? (just a fun cosmetic addition) (At this point, one of six hero models will appear, corresponding to your choice. For example, a ranged strength hero will be a turtle.)
- Which ability would you like from this set of five? (repeated 5 times, with a different set each time)
All the abilities are available to every hero archetype. This means there are many possible combinations, but very little variation from game to game (all eight players are offered the same sets).
A number of abilities are marked in red: these are only usable on the surface. This includes Puddle Jump (a.k.a. Blink), weather-themed spells like Blizzard and Monsoon, and an ability which summons a flying minion.
A thought which amused me was that if there were any global abilities in the game, they would rather unusually be "global" only to the player's current plane. So if a hero like Zeus was ported from DotA Allstars, his ultimate (which would presumably be red since it's weather themed) would only strike enemy heroes on the surface, introducing a new layer of strategy when using that ability.
There's plenty of potential for more great interaction like that in a parallel-terrain game (how about items that only work underwater?), though Water War doesn't explore it much further than I've already described.
There are a couple of other things to note about the different water levels. Firstly, submerge/surface have no effective cooldown, which is a bit weird and makes it possible to continuously juke between planes to avoid being targeted. The mechanic would probably benefit from a condition that discourages spamming; the specifics could have big implications.
It should go without saying that you can't submerge/surface on land, which makes being ashore that bit safer from ganks, but also cuts off an escape route.
I would also like to point out that the sound of water is a constant presence: splashing waves while on the surface, and a more muffled bubbling when down below. I really like this attention to detail, reinforcing the map's most unique feature while improving the ambiance.
At their main base, teams can also purchase 10 permanent Troop Upgrades. Five of these are stat upgrades which affect every troop, while the others add extra troops to each wave. One of the extra troops is flying and hence surface-only, while another (crabs) are seabed only.
A lane-pushing game executed on two parallel planes turns out to be just as cool as it sounds, and Water War does a great job demonstrating the concept's potential. I would really love to see this pushed further: the idea of having to constantly communicate with your allies about the other plane is fascinating, and so many cool skills and strategies could emerge if this system was given further depth (pardon the pun!).