Eternal Empire post-mortem

With Eternal Empire bidding the ladder farewell, I figured it was worth taking some time to do a post-mortem of the map much as I did with Golden Wall, whose recap and review you can read here.

Out of the Clouds

Eternal Empire is the spiritual successor to Cloud Kingdom, which became the first map of mine to be used on the ladder way back in 2012. Universally praised, I’m of the opinion that the primary reason Cloud Kingdom went on to be considered one of the best maps ever created is because of how it embraced the concept of ‘the longer path gives a better attack angle’.

The main, natural, and third base setup on Cloud Kingdom

With the aid of destructible rocks outside the natural and a larger choke at the third base, Cloud Kingdom allowed players to establish a three base economy with a degree of safety rarely seen in that era of StarCraft II mapmaking.

That wasn’t the only thing that set Cloud Kingdom apart, however. The same destructible rocks that aided defenders could also be exploited by an attacking player, affording them opportunities to punish greedier builds. The end result was a map that saw a wide variety of ever evolving strategies.

The same structure can be seen on Eternal Empire, albeit with one major difference. The natural base and the ramp were shifted to be closer to one another. This made it so the destructible rocks could be included in the process of walling off one’s natural part. A closer ramp also meant that there was less risk in deploying units at the top of the ramp during the early game, as they could simply retreat behind the wall if necessary

By embracing the principles upon which Cloud Kingdom was built, Eternal Empire encouraged greedier/high tech strategies and macro games. But the goal when creating Eternal Empire wasn’t merely to make a map tailored to the late game, it was to create one that would foster the same wide range of gameplay as Cloud Kingdom.

Blue circles: The Defender’s bases
Blue lines and arrows: The Defender’s army set in a concave
Red arrow: The Attacker attacking through the shortest path
Orange arrow: The Attacker going around to attack blue from a better angle

Not Only Bigger, but Better

StarCraft II has changed tremendously since the nascent days in which Cloud Kingdom was a tournament staple. After seven years, innumerable balance patches, a pair of expansions and a complete overhaul of StarCraft II’s economy, Cloud Kingdom no longer stands as the innovative marvel it once was.

Where Cloud Kingdom had the luxury of existing in a period where games were largely determined in the areas around the second and third bases, the 12 worker start introduced in Legacy of the Void rendered this type of design outmoded. If Eternal Empire were to succeed as Cloud Kingdom had, it would need to embrace similar tenets, but apply them to bases beyond the third, as well as areas of the map which saw greater interaction between players than they would have had the map been played in Wings of Liberty.

The first, and most obvious change, was simply enlarging the map. Cloud Kingdom used a 126×132 tileset with a 42 second main to main rush distance. Eternal Empire clocks in at 140×140 and 46 seconds. Legacy of the Void’s economy requires rapid expansion as individual bases have less resources than they did when Cloud Kingdom was in use, so bases had to be added to occupy the new space. The addition of bases and attack paths was intended to force players to spread themselves thinner in the mid game, creating dynamic gameplay full of skirmishes and counter attacks, while also providing enough bases to prevent a split map situation should the game evolve that way.

Side-by-side comparison of the two maps. Notice the same placement of paths in green and blue. The path marked in red was added as an alternate avenue to the highground fourth base as the shorter path now features a ramp.

Towers and Terrain

Two of the largest factors when it comes to determining how a map incentivizes players to interact are Xel’Naga Towers and attack paths. Cloud Kingdom’s Xel’Naga Towers (neutral, invulnerable structures that, when activated, provided vision in a 22 tile radius for the player whose unit was in contact with it) were placed on the map to provide a player who wished to expand vertically rather than horizontally with vision of oncoming attacks. This meant that, in theory, while the base was more exposed than the horizontal third, it would offer a closer foothold from which to launch attacks against a player who expanded horizontally, while also giving enough notice to rally one’s forces to defend the vertical third when necessary.

It rarely played out that way, however. Not only was the tower itself placed directly below a high ground, but that same high ground allowed players to approach and attack the vertical third practically unimpeded the high ground leading into the vertical third created untenable situations for the defensive player. When you add this to the fact that the fourth base, should one attempt to expand vertically, was so far away from the third, and you can see why as time went on players began to adopt the horizontal path almost exclusively.

The Xel’Naga tower and the vertical third base on Cloud Kingdom

I didn’t want Eternal Empire to limit players in the same manner Cloud Kingdom had when it came to expanding, but having all the viable expansion paths in the world doesn’t accomplish anything if players have to reason to prevent their opponent from expanding. Backwater is an example of a map that offered two many bases and too few ways to punish players for taking them. The end result was that players rarely left the safety of their defences and games quickly stalled.

I didn’t want Eternal Empire to suffer in the same manner that Backwater had, but I still wanted to include an alternate vertical expansion. I knew that the placement of the Xel’Naga Tower and the terrain around it would play a critical role in determining whether or not I was able Eternal Empire would be able to succeed as Cloud Kingdom had.

Eternal Empire features three paths which cross the split axis (one for each player and one neutral), a more traditional layout which has fallen out of favor in recent times due to its proclivity to cause split map situations. The issue at hand was how to get the most of the three paths without causing games to stall out. I ultimately settled on placing the Xel’Naga Towers on the map’s split axis, (the line that divides the bases each player is most likely to take in a split map situation), as well as on the high ground rather than the low ground, which is where they had been located on Cloud Kingdom. The Xel’Naga Tower were then connected to the main base using the double ramp structure seen on maps like Lost and Found.

Green circles: Xel’Naga Towers
Blue circles: The base that can be taken by the player spawning nearby
Yellow line: The map’s split axis

With the Xel’ Naga Tower positioned on the high ground, I took advantage of the terrain to create the vertical expansion path I mentioned earlier. This expansion path had risks associated with it, but it also provided a great foothold to attack the opponent, especially in Terran vs Zerg (as was the intention with Cloud Kingdom nearly a decade earlier). The goal of the vertical path was to create a viable alternative rather than to supplant the horizontal one entirely, and I believe that ended up being the case.

Rich Gas Geysers and Forcing Interaction

Just as Xel’Naga Watch Towers and attack paths can play a role in incentivizing or disincentivizing action during various stages of the game, rich vespene geysers can fulfill a similar role.

Expansions with rich geysers have become a common feature these days, but early efforts to adopt them did not go so smoothly. On the ladder map World of Sleepers, players were able to take rich gas expansions very early in the game which allowed certain timing attacks, specifically the roach/ravager all-in in Zerg versus Protoss, to arrive before the defender was able to properly respond. Since then, mapmakers have tended to place rich gas geysers further away from starting locations.

Eternal Empire, however, has two sets of expansions with rich geysers. The first one is an optional lowground fourth base. As you can see in the image below, there is a significant risk when it comes to taking this base as it’s vulnerable to ground attack from three directions whereas the safer high ground fourth only exposes the player from one additional direction. At the same time, the expansion had its positive features as well. That expansion wound up being a popular option which led to a lot of army movement from both players as they were forced to attack and defend that expansion from a variety of angles.

The attacker can attack the lowground fourth base head-on and then rotate to attack from the high ground

In addition to the Rich Vespene Geyser, the positioning of the low-ground fourth also had an impact on whether or not a player opted to take the riskier, low ground fourth when they could take the high-ground fourth base (that could only be attacked through a pair of smaller chokes). 

The lowground fourth was placed in a very open area that allowed players to move their large late-game armies more comfortably. Starcraft II multiplayer map design places a lot of emphasis on corridors, mostly to prevent Zerg players from surrounding their opponents easily during large engagements. All in all, I’m happy with how the lowground fourth, high ground fourth and vertical expansion paths turned out. Eternal Empire gave players a lot of options which is always a good thing. It also gave me some food for thought as to how to deal with wide, open space and how they needed to be paired with smaller corridors to create a map that remains dynamic throughout the game and full of points worth contesting.

How It Played Out

The most important feature, the combination of choke and longer paths played as expected. This feature is often used by many Starcraft II map-makers and it wasn’t much of a shock that it functioned as expected.

In regards to the rocks near the natural, this has been featured constantly through the years since it first appeared on Cloud Kingdom. It remains a tried and true feature that improves a map regardless of expansion.

The open area in front of the lowground fourth was used more often than expected. That area was very important because it allows the attacker to attack the lowground or highground fourth base from one spot. That lowground area is also on the direct path from the natural base. You can see that in the picture below.

The attacker can easily choose to attack any of the fourth bases

The lowground rich gas expansions were this map’s pleasant surprise when it comes to what I’ll take away from it. It was intended to be taken late in the game as the 6th or 7th base, but I hadn’t anticipated players’ willingness to attack the base because of the choke points leading up to it. As time went on, and players got a better grasp of the map, it created the types of small skirmishes that are always popular among spectators, and allow the elite pro players to separate themselves from their peers.

It is definitely a feature to take into account designing how a map will function in the late game. I already reused this feature in my recent maps.

Both players can hardly engage each other around this base

You can see below the final race balance stats for Eternal Empire.

Source :


After three seasons on the ladder (thanks in part to Purity and Industry, which will be covered in more detail in the future, being an imbalanced mess)  Eternal Empire logged more than 4000 tournament games, making it the most frequently played map I’ve ever created.

I think Eternal Empire succeeded in adapting Cloud Kingdom to Legacy of the Void. The combination of chokes and longer paths played well. While the Xel’Naga Tower, Rich Vespene Geysers and various expansion options created points of contention that forced players to multitask and split their attention as games entered the later stages.

The game below is a great example of the behaviours created by the features of the map. It is a long game, as we came to expect from Eternal Empire.

This article has been edited by Teamliquid’s Mizenhauer.