Typical game progression

This is a guide explaining how a typical game progresses, after a typical opening. The game can be thought of as being organically split up into a few phases, each with a characteristic set of units and goals.

• Note that these are general scenarios - depending on the map and factory match-up the game can play very differently!
• From a 1v1 perspective
• (wip)

Raider phase

The raider phase is the first phase in a typical game. It is defined by a few characteristics:

• Most of the map is untaken by either player.
• No defenses covering most areas.

Due to this, the mobility that raiders have tends to make them the dominant unit class. When the map is fortified with light defenses, raiders are much less useful and it will be time to switch to something else.

Expansion

You will want to expand as fast as possible here, and try to grab at least 50% of the map. Try to have two groups of constructors moving around the map taking mexes. Near each mex cluster you can put some light defences, but do not overbuild defences early game, and in non-critical locations (i.e. not a choke point or the centre of the map). Run around the map with your raiders, keeping track of where your opponents raiders are as well.

You should be able to defend your expansion from enemy raiders with some light defenses and some of your own raiders. Since raiding properly is considerably more difficult than expanding, you should be encouraged to expand as fast as possible.

• Try to expand much faster and in a more risky manner than you think is possible for a few games. You might be surprised at how much greed you get away with! It is much harder to punish greed than it is to be greedy. Doing this will also help you learn the safe maximum limits for expansion.

If you succeed in this phase of the game, you will have a massive eco advantage and will be able to swarm your opponent to death with units.

Energy production

A very common mistake players make is that they don't build enough energy structures. This leads to a situation in which your metal income exceeds your energy income and you are unable to spend all your metal (called "e-stalling"). Having 1 constructor dedicated to only building energy structures can solve this issue.

Raider Usage

You want to have good radar coverage of your side of the map and keep your raiders as close to the enemy as possible. This puts pressure on them, and also forces them to keep their raiders near their base, away from your expansion. Against good players you will not be able to do much damage with raiders, but that does not mean you have accomplished nothing by keeping your raiders near them.

• Because of the threat of your raiders, they are not able to "naked expand" (very fast expansion with minimal or no defense). If you allow your opponent to naked expand, they will typically just roll you over a few minutes later with a massive eco advantage.
• Forces your opponent to keep their own raiders near their own base to defend from yours. It can also force them to build more defense, slowing down their expansion and reducing the amount of pressure they can put on your own expansion.
• Gives scouting information. By running around at the edges of your opponents territory you will be able to see what they are up to. If they are trying to rush a heavy unit or do something silly you will often just be able to overrun them and win.

If you find yourself on being the one that has raiders at their front door, things are a little more challenging, but don't panic.

• Try to expand where your enemies raiders are not(with that other group of builders on the other side of the map that you have...right?).
• You can slowly creep forward with LLTs and the protection of your own raiders.

In higher level games what usually ends up happening is that both players are good at raider control and don't really kill much of importance on either side. While raiders are chasing each other, each player is slowly building up and fortifying territory as they move closer to the center of the map.

• Fortifying territory means building maybe 1 or 2 defensive towers near mex clusters and also putting some defensive towers near some critical locations to block off pathing. You should get essentially a full line of sight across your front line, so your opponent cannot sneak units into the middle of your territory without taking some damage from towers and you not knowing about their movements.

Note that you do not need to kill anything to have a successful raider phase. Your primary goals are to expand and grab territory while slowing your opponents expansion to a reasonable pace, and also have the energy to use all the metal you took control of. Your raiders will be useful later, so try to keep them alive. There is a "reasonable maximum speed" at which players can safely expand, and as long as you make sure your opponent doesn't exceed this and you are close to it, you will probably enter the later stages of the game on equal footing. Not every game is won or lost in the raider phase, and in fact, probably most aren't.

Often you will see a location that is lightly defended with towers, and you will correctly assume that you can run into it with your raiders and kill everything. However, this is a risky (and often unnecessary) thing to do.

• There might be some defense you don't see, like nearby units ready to help.
• Killing towers with raiders is not cost efficient, so the payoff might not be that good.
  • This could lead to your opponent taking a temporary raider number advantage, which could put you on the defensive and actually put you behind from where you were before, as you are no longer able to exert as much map pressure.
• Committing your raiders to an attack like this open you up for the possibility of a counter-attack, and since your raiders are somewhere else, you might not be able to defend.

Finding a lone commander

Sometimes your opponent may be a bit greedy and have their commander out alone. If it is a low level you might be able to kill it with your raiders if you have like 10 or so. It is almost always worth it to kill a commander. Some raiders like kodachae or daggers are bad at this, but others like scorchers are amazing at it.

• Spread your units out right before it dies, as they have a death explosion which could wipe out your raiders if they are really close to the commander.

Why not other unit classes?

Riots

It may seem intuitive to make riot units in this phase of the game. "They're good against raiders, aren't they?" you may say (correctly). However, their downside is that they are very slow. This makes them unusable for offense, as your opponent will see them coming and be able to easily respond. Also:

• Early game, lone riot units can be overwhelmed by raiders.
  • You can use line move to spread out your raiders (preferably in a concave) and then just run at the lone riot unit and kill it. Try to get your raiders to encircle the riot to minimize any AOE damage it may do.
• Light defenses are effective against riots, as riots are DPS, not HP focused. Light defenses will take a significant portion of the riot's HP away before the riot is close enough to fire. What usually happens is that the riot maybe kills one or two defensive towers and then just dies(very cost inefficient).
  • Due to targeting oddities, the riot will often stay locked into firing at a defensive tower. This gives you an opportunity to swoop in with raiders and kill the riot quickly, before it even gets a chance to fire at your raiders.

Because of the above reasons, they do not pose much of a threat (unless you don't scout a riot rush of some sort and lose anyway).

• You can just run past the riots and ignore them. Because of this, players tend to spread out their riots to try to cover every location so you can't run past them.
  • Notice how this contributes to the first point.

The correct way to deal with an opponent making riots is to just expand faster than they do - they won't be able to punish this. When you inevitably get superior eco, you can just overwhelm them. Try also running around with your raiders near your opponents front lines. They will often be scared by this and will need to be constantly re-positioning their riots to defend from a possible raider run-by into their base. If you see that they are doing this, you can expand even faster, as they don't have any way to punish your expansion.

Any other class

Skirmishers, artillery, assaults - all of these do very badly against raiders, so are not worth building at this point.

Importance of radar

Radar coverage is very important to get in this phase. If you do not have it, you have to play defensively in case your opponents tries to raid some of your expansions. The alternative is building tons of defenses everywhere, but this is a losing strategy, as it leaves you unable to punish your opponent for expanding. If they expand they will just overrun you with units. By building radar you can reduce the amount you spend on defense, and can use it on offensive units instead. In the worst case scenario, you prevent greedy expansion from your opponent. In the best case, you just win because they were too greedy and have no units.

Dealing with defensive players

A strategy that many have trouble dealing with is when your opponent just builds lots of defenses at every expansion site. The best way to deal with this, paradoxically, is to just ignore them and focus on expanding yourself. If they want to sit in the corner building defense, that is fine (for you). Since they have spent so much metal on this, they won't be able to prevent you from expanding, so just take the whole map, make lots of eco, and then come to their base with artillery and win. There is really no situation in which fortifying yourself into a small section of the map is a winning strategy.

End of raider phase

Eventually, the map will become covered with a line of defenses from both players, partitioning the map roughly in half. This limits the mobility advantage that raider have, and it becomes time to switch to something else. Some areas might be lightly defended, and if you know the enemie's raiders are not close, you can punish this, but by this point people often have full radar coverage and its not that difficult to spot and defend these sorts of things.

Midgame phase

In this phase, strategic diversity opens up significantly. Players typically transition out of raiders into some of the following:

Skirmishers

A common strategic switch people make is a shift to building raiders skirmishers rather than raiders. These units are capable of killing light defenses fairly well, so you can start pushing back your opponent and try to grab more territory. Use your raiders (which are hopefully still alive) to protect your skirmishers from harm. It is also common to see a few riots dedicated to protecting your skirmishers.

Assaults

For some factories, it is possible to switch to assault units. These units will be able to punch through light defenses (unlike raiders) and do some economic damage to your opponent. Some examples:

• Thuglaw - Outlaws and Thugs - this combination from the shieldbot factory is a very potent assault force. It is good against raiders and light defences, giving it the potential to do lots of damage to an unprepared opponent.
• Ravagers - Fast assault rovers that can be used for raiding. They are able to eat through light defences, and due to their speed it is harder to position raiders to defend against them.

Air switch

A very typical midgame transition is switching to air. Air units are typically quite a bit faster than ground units, and do not suffer from pathing difficulties that ground units do. It is advantageous to get air units for a few reasons.

• They are very good at shutting down raiding, both from raiders and fast assaults like ravagers.
  • These units are difficult to chase down with more typical midgame units like riots or skirmishers. It is often a losing move to chase units this way, as the lack of riots/skirmishers at your frontlines means your outermost expansions will probably be taken from you.
  • Air units are fast enough to catch anything, and typically will take little return damage.
  • Helps further consolidate your front lines as you no longer have to worry so much about being counterattacked as much.
• Air gives you the ability to scout easily.
  • You can see what your opponent is up to. Are they rushing a strider? Lots of fusions? Other greedy things?
• You can punish very greedy behavior.
  • Kill expansions with minimal defense. For example, if they just have like 1 LLT and defender.
  • Kill undefended eco structures(fusions,windmills).
• Forces your opponent to divert some metal to anti-air(if they don't want to die).
  • Can take some pressure off your front lines, as they can't send as many ground reinforcements. Anti-air units are pretty useless against anything that isn't air.
  • Typically this makes both players back off on the front lines for a bit and get readjusted for air game play.

There are two air factories, which play very differently from each-other.

Gunships

Gunship units are a little slower than their air counterparts, and they also are DPS focused, instead of alpha focused like planes.

Fortification

In the midgame, players will sometimes fortify certain locations on the map with heavier defenses such as stingers or stardusts. This happens at central locations of the map as it gives you a sort of staging point that you can keep your units at safely. Heavier defenses generally require a specialized response of artillery or heavy units, so by building some, you can buy yourself some time as your opponent is figuring out a way to deal with the heavy defenses. Stingers are especially tricky at this part of the game, as they are the first type of tower that can actually fight skirmishers well. If you find yourself losing ground to skirmishers or expect them soon, it may be a good idea to put up a stinger. Stingers do not do that well against lots of light units, so make sure to keep building lots of LLTs(or even add a stardust).

Lategame

Both players with have built up sizable armies of skirmishers/riots/assaults and will probably have some air presence. The map will be more fortified, and it will be difficult to make progress with "lighter" units.

Eco

If things have stabilized in the midgame, it may be time to build some eco.

• Build all the available geothermal power plants(they are super efficient!). If you feel that some are very safely located, upgrade them.
  • Upgraded geothermals will often pay for themselves within just 3-4 minutes. As a bonus, they explode violently on their death. If the area is clear of allies, they can make for a nasty surprise to nearby enemies. When followed by a quick reclaim and rebuild, this will give an additional boost to your economy at the cost of your opponent's.
• Connect your energy grid together. The more mexes you connect, the more efficiently energy will be distributed, and you will end up with more metal.
  • Overdrive is VERY efficient at low levels of energy. Something like 2 e/s can increase production 50%.
• Build fusion energy reactors. Make sure to scout before starting, as it can stop your unit production for a minute or so. If for example you scout your opponent switching to air or preparing a massive raid, it may be better to make sure you can counter their strategy before ecoing, as otherwise you might take heavy damage.

As with expansion, it is much harder to punish greedy eco-ing than it is to do it yourself. Try to be a greedy as possible and learn what the safe limits are.

Heavies

At this stage in the game you will start to see heavies coming out. "Heavies" are units that are generally 1500+ cost. Most of them massacre the lighter skirmisher/assualt/riot balls that are predominant in the midgame, and they also can stand up the to defenses built in the midgame(ie they can actually kill stingers). Units such as cyclops, sumo, grizzly will be often seen.

Bot specialist units

The bot factories do not really have "heavies", but they do have more expensive upper tier units that can be used to fight heavies of other factories.

• Cloaky factory will start to build Snipers and area-cloakers.
• Shield bots can build felons and aspis. Felons supported by aspis can deal a very large amount of damage very quickly, burning through the health of almost anything. Racketeers are commonly added too, and these are good at disabling heavy units.

Light striders

Someone putting down a strider hub and making either a scorpion or dante is quite common.

• Dante is very good against skirmisher balls as its "D-gun" can 1 shot most of them. It is also one of the faster striders so it can get into action quickly. Due to all its aoe damage, it massacres riots and raiders as well. It fights assaults decently, but be careful, it actually loses to most of them by cost. You need to retreat and repair it to get full value out of it.
  • Be carefull with your own units around the dante. The dante causes alot of chaos and fire and flames everywhere, and this can also hit your own units and kill them.
• Scorpions are invisible and have their EMP- D-gun. This can be used to sneak up on valuable targets like commanders or a bunched up set of units, stun them, and then kill them. Scorpions are probably more of a support unit, as their dps is much lower than a dante, and also get kitied by skirmishers easily.
  • Scorpions beat dantes quite easily, especially if they get their stun off.

Late-Lategame

In this phase you will see heavy striders and some of the more exotic tools available to the player.

• Bertha, effectively the big brother of mobile artillery units.
• Nuke
• Ultra-heavy porc
  • Desolator, often put on terraform to increase range, will quickly destroy anything short of a strider
  • Lucifer, while weak to smaller units, can snipe even the heaviest assaults (including striders) and repel most artillery
  • Cerberus as counter-battery against artillery and to deny large areas to ground troops
• Paladin/Detriment
• Starlight/Zenith/DRP
• Singularity

Conclusion

Note that this is a general overview. Sometimes people may rush heavies in the midgame, or eco during the raider phase or whatever else. Zero-k is a very flexible game, and there is no really hard or set meta-game like in starcraft 2. Lots of game play is map-dependent or match-up dependent.