As promised in the previous post, this is about the mind game regarding the use of Oracle in TvP. To be more exact, it is about how what to expect when you see an Oracle.

Oracle is a new unit in Heart of the Swarm and it has been a big part of the metagame shift in TvP.

The best way to describe Oracle to someone who has not played Heart of the Swarm is that it works like a Banshee. Similar to a Banshee, Oracle is an air unit which can only attack land, and is often used to harass mineral line by killing workers. Oracle does not have cloaked ability but it kills workers much quicker with Pulsar Beam. The game can end within seconds if the Oracle is left unattended at the mineral line.

From Terran’s perspective, the best way to deal with it at the time frame is either by positioning your Marines at the places where the Oracle attacks, or simply plant a Widow Mine at the mineral line. However, issues arise beyond merely positioning units to defend against Oracle harass when Terran players expect Oracle in the early game. The followings describe what Protoss can do after getting Oracle.

One base all-in

PartinG vs. YoDa in IEM (Game 5)
PartinG vs. Flash in MLG (Game 2)

An one base all-in is perhaps the most straight forward follow up Protoss can do after using Oracle to harass. Oracle’s attack can melt the Marines and end the game if the Terran player did not target fire the Oracle. But it is easier said than being done due to the mobility of the Oracle. Its mobility gives the Protoss player more room to micro it, while the rest of the units constantly deal damage. In the fifth game between PartinG and YoDa in IEM, PartinG failed to break the bunker and hence his all-in failed. The bunker was so closed to being focused down, and the result of the game could have turn out differently. If YoDa did not have the scvs positioned at the bunker or the battle was not done at the ramp, the all-in could very well be successful.

PartinG also did a well executed one base Oracle all-in against Flash in MLG game 2.

Two base timing

MC vs. Mvp in MLG (Game 2 and 3)

MC demonstrated how threatening Oracles can be if they are kept alive for a subsequent two base attack. First of all, the Oracles can pin the Terran in his/her base, which means the drop is less likely to happen. If Terran still chose to drop, Oracle will give enough intel that a drop is coming. In game 3, Mvp positioned his Marines accordingly to anticipate the incoming Oracles, while MC hid his Oracles and attacked when he had four. The Marines got destroyed. The tempo of the game fell to MC and he eventually won with a two base timing. In game 2, MC attacked from the front with four Oracles too, and it got me thinking whether four is the magic number.

Phoenix control

MC vs. Mvp in MLG (Game 1)

MC had the best possible start with the successful Oracle harass. He then transited into Phoenix. The role of the Phoenix is to control the map and prevent drop. For the whole game, Mvp did not have a chance to leave his base. Well played.

Hallucination

First vs. YoDa in IEM (Game 3)

Hallucination no long requires research in Heart of the Swarm. First created a hallucination of Oracle and flew it into YoDa’s base while he was producing actual Oracle in his base. It had three main purposes. One was to scout the defense at the base. Is there a Widow Mine? Where is it positioned? How many Marines are there? The second reason was to deceive the opponent. YoDa now saw a fake Oracle, how will he react when the second one arrives? It planted a seed in his mind. Is the second one real? If YoDa assumed that the second one was also a hallucination, then he would definitely take some economical damage. The third purpose was to set off the Widow Mine. When the real one flew in subsequently, the Widow Mine would still be having cool down.

Anti-drop

PartinG vs. Flash in MLG (Game 1)

So far I have been highlighting the offensive options the Protoss players have with Oracles. It is important to understand that while Terran players are wary of Oracles, Protoss players are also anticipating drops. With the Medivac boost, Protoss players are having a much harder time to defend against drops. Clearly, one of the way to anti-drop using Oracle is simply to pin opponent in his base by moving the Oracle around Terran’s base. PartinG is much more innovative than that. He used Oracle’s Envision ability to counter Flash’s drop. Envision is rarely used. It casts a spell on enemy units, and the owner of the Oracle has vision of the affected units. PartinG cast Envision on the Medivacs of Flash, which allowed him to trace the movement of the drop ships. Therefore, PartinG had close to perfect information about the movement of Flash’s main army, and specifically the Medivacs. Drops are much easier to defend when you know they are coming. I must say I’m very impressed by PartinG.

PartinG created only one Oracle in that game. He moved it to the edge of Flash’s natural, which was spotted by Flash. PartinG did not try to kill one or two workers with it. I thought that was brilliant. An Oracle that did not attack could be a hallucination. Terran would be anxious about “Is the next Oracle real?”. Flash did not see anymore Oracles as PartinG did not create more and did not harass with the only one. Flash could very well mistook a real Oracle as a hallucination subsequently. Well played.

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I have listed options that Protoss can do with Oracles from Protoss’s perspective. Since this is TerranCraft: From a Terran’s perspective, I want to discuss about how the options could play affect Terran’s game play.

First of all, how can Terran know Protoss is going for Oracle?

The first scv scout should scout two gas. It is very unlikely that the player is going for Oracle if there is only one gas.

Then, what should I do if I scout two gas?

For the current metagame, it is safe to assume that there will be Oracle. The first Oracle should pop up at around 6:30-7:00, and the time it reaches your base would vary if he chose to proxy the stargate. In general, expect the first Oracle to be at your base by 7:00 to 7:30. If you go for 15 gas build, plant Widow Mine accordingly. Nevertheless, the position of Marines is crucial.

What should I do if there is indeed an Oracle?

I have seen pro players chose to drop, while some chose to defend. Personally, I will opt for defend. This is because, you need to have decent amount of units to defend against the Oracle. When you choose to drop with the rest of the units, they are unlikely to do damage with the Photon Overcharge. A Widow Mine drop, which is more effective against Photon Overcharge than Marine drop, is unlikely to be effective. Based on the newer games I had seen, Protoss players now plant one cannon at the mineral line to defend against Widow Mine drop. Therefore, in my opinion, it is better to defend against the Oracle. If you can kill an Oracle or two, you’re already ahead. Most importantly, scout! Try to deduce what the opponent is doing behind the Oracle.

What should I look for when I scout then?

If opponent is not doing a one base all-in, the Nexus should be down by the time you see the Oracle. If you can see Nexus, then you can deduce that it is not a one base all-in. At this point, it is hard to tell what opponent plans to do. But it is important to know whether he plans to all-in at that time. The chance of it being an all-in is even higher if you do not see a Mothership Core.

What if I scouted 2 gas, but there is no Oracle by 7:30?

Scout and scan. The first thing to check is whether there is a Nexus. The second question will be whether there is Starport. If there is a Nexus and a Starport, then he could be hiding the Oracles and strike when it reaches a critical amount, just like how MC played against Mvp. You must build turrets.

If there is a Nexus and no Starport, it could be Dark Templars. The opponent has to be going for some kind of tech behind the expansion.

If there is no Nexus but there is a Starport. An Oracle all-in is incoming.

If there is no Nexus but no Starport, there is a high chance of blink all-in. Get tanks. A four gate is also possible.

What if opponent has multiples of Oracles circling around?

This is a sign of threat. He will attack once you tried to move out. Or even attempt to take out a group of your Marines with the high dps. You must build turrets. One in each mineral line and one at the entrance. Do not save the money. It is naive to think that you can hold without specific reaction if your opponent has invested so much into the Oracle tech. It is only normal to invest in defending against the Oracles.

Get vikings.

What do I do if opponent is playing the PartinG anti-drop style?

Expand.

The purpose of using Envision on the Medivac is to know when and where you are dropping. Thus, he will need to have his units in his base to defend for the strategy to work.  It gives you more liberty to expand.

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Just a side note. I notice that pro players will scan the natural of the opponent to see if there is a Nexus. It is absolutely normal. However, the positions of the scan were often not optimized. It is cliche to say that you need to look for something when you scout or scan. A scan can do more than just checking if there is a Nexus.

Pro players often scan right on top of the natural if they want to see whether there is a Nexus.

This is how it could be done better.

The images are taken from game 1 of IEM final between YoDa and First. YoDa scanned in between the natural and the main of First. The scan is just enough to see if there is a Nexus, which serves its primary purpose. Moreover, it gives YoDa further vision of the main than merely scanning right on top of the natural. Because of the position of the scan, YoDa saw the two gates in the main. This is what I meant by optimizing a scan.