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Written by Garrett Shaper
Art by Mallory Brangan

Simcity in Starcraft II

Members of the Starcraft community will sometimes say a player has "good simcity" when talking about their structures. What are they talking about? While the term "SimCity" originally comes from the classic game of the same name, in Starcraft the term 'simcity' is used to describe the structures a player has placed in a specific way to create a strategic advantage. In this article I discuss simcity in Starcraft II in three parts: fundamentals, common practices and advanced techniques.

Part I: Simcity Fundamentals

While there are advantages and disadvantages to every simcity layout in Starcraft II, all layouts have a few things in common. Here are some points to consider the next time you place a structure.

1) Every Placement Counts - Most effective build orders have an optimal simcity layout to maximize their effectiveness. Whether you are cheesing with proxy aggression, walling off for a one base timing attack or fast expanding to your natural, your first building's placement is the first step towards your build order's goals. While some aggressive build orders aren't as concerned about how a counterattack might impact their base, there is always an optimal simcity layout to support each build.

2) Nothing Lasts Forever - A good simcity early in the game can become a liability later on. For example, hidden tech on the map is great until your opponent sees it and it becomes an expensive and difficult point to defend. Five early Spine Crawlers might deter your opponent from attacking on the ground, but it will encourage them to attack from the air or from a different angle where your 750 minerals worth of defense will not help. Wall-offs are designed to hold off early pressure, but once your opponent sees your wall it begins to lose value as a good opponent will not attack into it unless they're sure they can crack it. When you start expanding, your original wall can get in the way if your army needs to get back and forth to defend from drops or harass around your base. If you hide behind a wall-off long enough and don't expand or scout enough, you will often find your opponent has outpaced you in ways that you cannot recover from, such as expanding faster or teching higher.

3) What They See Is What They Think They Get - Good simcity can deflect good scouting. The buildings that are easiest to scout are also the buildings your opponent uses to judge what your capabilities are. Do you have a lot of static defenses? Is your tech near the front of your base where it is easily scoutable by a harvester? Do you have a large, unupgraded army at the top of your ramp? Your opponent will make strategic decisions based on this information, and the easier they can scout your key buildings and army, the better prepared they will be to deflect your build. Sometimes having a tech building near the front of your ramp "accidentally" while teching to Cloaked Banshees with hidden Starports can cause your opponent to react incorrectly and give you a huge advantage.

4) What The Tech? - While hiding tech structures where they are unlikely to be scouted can give your attack the element of surprise, keeping your tech structures near your army allows you to protect them from being picked off from harassment and possible scouting as well. These decisions are often dictated by the matchup, the map and status of the game, but worth considering. In the recent NASL Grand Finals match between MC and PuMa, MC had his Twilight Council destroyed numerous times, which impeded his upgrade of Zealot Charge as well as prevented him from upgrading Forge upgrades beyond 1/1. While they fact that this tech structure was built was probably less of a surprise to PuMa, the fact that MC didn't build it near his army where it could be protected meant it was easier to snipe with Medivac drops in multiple games.

5) Everything Has A Cost - Complex simcity takes away more mining time as the harvester has to travel to and from the simcity. Build orders such as 2 Rax, 4 Gate or Fast Speedlings that benefit from the fastest possible build order speed to be effective often care more about missing mining time than their simcity.

Part II: Common Practices

In Starcraft II, the wall-off is the most common and effective simcity strategy in the game. Like a well balanced army composition, the wall-off has greater value than the sum of its parts. There are many benefits to a wall-off, including:

• Protects your base from early aggression
• Prevents easy scouting with harvesters
• Allows you to hide tech structures deeper in your base
• Forces your opponent to spend additional resources/tech to scout
• Prevents cloaked units (DTs, cloaked Ghosts) from entering your base undetected
• Helps prevents proxy Pylons from being placed within your base
• Allows your ranged units free hits on incoming units with shorter range
• Creates a chokepoint that reduces the effectiveness of incoming aggression

The Zerg race was designed with the capability to produce more Zerglings than the early Terran or Protoss armies can handle. On many maps, Zerglings could quickly overrun the T/P base quickly without a proper wall-off. In the early beta, Speedling all-ins were more common. As we approach the one-year anniversary of Starcraft II, standard Zerg build orders against Terran or Protoss are designed with the expectation of a walled-off opponent. Many Zerg players use their early resources to either fast expand or fast tech to something more powerful.

Against Protoss, wall-offs can help deflect early Zealot rushes and prevent Dark Templars from sneaking into the mineral line undetected. They can also temporarily slow down a incoming 4-Gate rush by creating a narrow choke that can be held with fewer units, though this is not always helpful as the 4-Gating player can simply attack the structures. If you don't have enough army units when a 4 Gate hits, no simcity in the world is going to help you (except maybe a bunker or other static defenses!)

The Terran wall-off is sometimes completed with Supply Depot, Barracks, Barracks when executing a 2 Rax aggression build order, but the effect is the same. Additionally, sometimes the 2nd Depot is built partially and halted to prevent the opponent's first scout from ever entering the base. Once the Barracks is completed, the building SCV then completes the 2nd Depot. This build order modification also delays the Orbital Command from being built by 100 minerals and is often accompanied by a fast double gas leading into Cloaked Banshees or another large tech jump.

Proxy All-ins

The trick to successfully executing a proxy all-in is to hide your structures in a location as close to your opponent's base as possible without it being in an area that is commonly scouted. While the topic has been known to anger and frustrate some players, the truth remains that a successful proxy all-in attack can be somewhat of black art. How you place your buildings in a proxy all-in strategy isn't quite as important as where you place them, but nonetheless there is always an optimal simcity layout to every strategy. I thought it would be fun to talk about a few of common ones that have been seen from Bronze league to the GSL.

Photon Cannon Rush

The sinking feeling in the pit of your stomach upon reaching your Protoss opponent's base and finding no Pylons anywhere is often immediately followed by one of two things: cannons firing on your base or Zealots streaming into your mineral line. First, let's talk about the oldest trick in the book: the Photon Cannon rush.

One interesting point I found relevant to this article is that Cannon rushes are basically offensive simcities. They are only as effective as the placement of the structures. Some cannon rushes are made dramatically more potent because the terrain of a map allows for clever, abusive placement of Pylons and Cannons. One of the more famous examples of easily abused terrain is on Xel'Naga Caverns, which happened to me last week on the Platinum North American ladder and a few weeks ago at Dreamhack Summer 2011 in game 2 of oGsMC vs AdelScott.

A Three Pylon Wall-in

MC's Probe scout gets into the back of the base and places three Pylons that form a wall to trap and protect his Probe inside. This specific simcity prevents more than 4 Probes from surrounding any one Pylon. When the Pylons finish, a Photon Cannon is made in the middle of the Pylons that can reach the Nexus. MC also made a backup Cannon behind this one to solidify the position.

One Cannon To Rule Them All:

Traditionally, Cannon rushes are fought by the defending player making a Forge and Cannons of their own to prevent additional offensive Cannons from being warped in. While this is sound reasoning in some situations, this particular positioning makes it difficult to fight back in this way as the first cannon can hit the Nexus and defensive Cannons will usually be too late to stop it from being destroyed.

Proxy 2 Gate

Even something as seemly straightforward as one Pylon and two Gateways can have different simcity approaches depending on how aggressive or safe you want your buildings to be from scouting and defense.

The Proxy Two Gate

Low ground / high ground: While one Pylon and two Gateways can be placed pretty much anywhere, there are some slick layouts that are harder to stop than others. On Xel'Naga Caverns, the above screenshot shows a lower Pylon followed by two Gateways in the opponent's main base. This can be hard to stop with melee units as they have to run all the way around the ramp and over to the Pylon, and by the time they scout any of it there are usually 3 or more Zealots moving in to attack the base. Even attacking the Pylon with Marines from above can be risky as a Zealot can pop out right next to them and get a kill or two.

Zoning Out Attackers

This above layout makes it difficult to attack the Pylon easily with any tier 1 ground unit, unless they walk all the way around to the back or risk standing right next to a Gateway. Given the speed that Zealots can be produced and Chrono Boosted out, the opponent will not likely have enough time to reach the Pylon to shut down the Gateways before the attack is successful.

Boxing Out Melee Units

This layout prevents melee units from being able to reach the Pylon at all. It is also off the beaten path from standard scouting and not within the vision of the Xel'Naga Watchtower. It is a little bit farther from the opponent's base though, so Zealots might get spotted en route to the opponent's base.

No one I talked to seemed to believe that Terrans or Zerg have any common proxy strategies in this current metagame. There were times over the past year when proxy Barracks were built on the outskirts of someone's base, then flown into an unrevealed area of the opponents base to produce marines. Sometimes Zerg will hide a base or Proxy a Hatchery in an opponent's base, but I haven't heard of this happening with any degree of success or regularity. Neither of these have noteworthy simcity concepts, either.

Hidden Tech Structures

Hiding tech on the map is commonly done with Terran and Protoss structures, but it can also be done effectively with Zerg. One trick worth mentioning for Zerg is hiding tech structures with an Overlord dropping creep.

An Unexpected Tactic

In this screenshot, an Overlord is providing the creep for a Spire to be built. The beauty of this is that two or more Hatcheries loaded up with larvae can surprise your opponent with a small fleet of Mutalisks without any warning, even if they have scouted your base multiple times. Dark Templar Shrines are often built in this manner as well, as the element of surprise is more impactful with these units.

Part III: Advanced Techniques

Fast Expanding

Every race fast expands sometimes, and this is usually influenced by the map and the matchup. There are countless ways to fast expand for each race so I will only talk about some of the more common ones here. One thing is for sure, good simcity plays a critical part in protecting the expansion before a decent sized army is available.

Zerg fast expansions don't utilize any simcity, they usually just plop down a hatchery somewhere in their build order and rely on forward scouting and army mobility to defend and protect it. Sometimes crawlers are used to follow up the expansion if aggression is spotted, but the depth of Spine Crawler placement could fill another article all by itself, so I wouldn't get into that here.

Terran fast expansions normally build the second command center inside their base, behind the standard Terran wall-off to protect it from both scouting and early aggression. Depending on the map, matchup and situation, they might not move it into position at the natural immediately. Often they convert it into an Orbital Command and take advantage of extra MULE and SCV production until the coast is clear. A Terran will sometimes then build a bunker or two in front of the natural expansion while flying their second orbital command into position to fully take the natural.

Protoss fast expansions rely on stronger simcity and usually open with Pylon, Forge, and Gateway blocking access to their natural, followed by a Cannon to protect the wall and a Zealot to hold the choke. Obviously this is more effective on maps where this is enough simcity to seal the entrance, but that's the idea. Maps like Xel'Naga Caverns and Metalopolis have wider openings to their natural and are more risky.

HuK vs Moon, Finals game 5, Dreamhack Summer 2011

HuK defended a 6 pool on Tal'Darim Altar with a full wall-off at his natural choke. The Pylon at the top is typically a Cybernetics Core, but HuK didn't have much time to spare as Zerglings were already on their way.

oGsMC vs FnaticSen, Finals Ro4 game 1, NASL

MC hard walling in to protect his fast expansion against Zerg. Typically the Cannon and Pylon placements are reversed, but it doesn't really matter - neither position defends from Roaches attacking the outer buildings from maximum range.

Closing Thoughts

Simcity can play a role in many strategies but it is most effective at defending your base from aggression. Sometimes when you see an SC2 pro setting up a simcity layout you don't understand, try to look at it from their opponent's perspective. Does the layout of their buildings make it harder for them to be attacked with a certain type of unit? What does this layout make it easier or harder to do in general?

Even a base with buildings loosely placed all over the area can be an effective simcity. Loose building placement is more commonly associated with build orders aimed at the late game, when drops and harassment need to be responded to quickly. The last thing you'll want to see when rushing to the back of your mineral line to defend against harassment is a tightly packed group of your structures in your way.

New simcity layouts appear regularly in a healthy metagame. When considering the layout of your buildings, consider the problem you are trying to solve. If you want to reduce the effectiveness of harassing air units, make sure there is plenty of free space for your anti-air units to get into position. If you want to reduce the effectiveness of harassing ground units like hellions or reapers, consider blocking one side of the mineral line so they can't easily circle around your base kiting your defenses.

In conclusion, remember that every time you place a structure, there might be an optimal place to put it. Reviewing pro games and replays will sometimes help you see these placements more often and offer you another minor avenue to improve your overall play.

Thanks for reading! I look forward to more in-depth discussions regarding race-specific simcity strategies.

Scraps!