Some of you all might have seen Artosis's tutorial of the "3 stalker" build to stop a 4gate rush, but I would like offer my own tested 4gate punisher.

If you watched the replay, Artosis's opponent was late on a cycle and lost a pylon unnecessarily, so we don't have a lot of evidence on its true effectiveness. I'm not saying the 3stalker BO doesn't work, but it will more likely fail if you miss the pylon deny...which is a tall order given the ninja potential of probes on other maps. It’s more of a "let’s hope I delay that proxy” build, that shows up anyway.

My suggested build is set to counter the 4gate with 1) faster tech, 2) better econ, and 3) more potential to win outright on a counter compared to the “3 stalkers.”

So what is this magical build? In a nutshell it's an immortal rush with early sentries. Some call it a 1gate-robo.

Because 4gate depends heavily on early stalkers, the natural counter is immortal, but if your opponent is warping zealots over your ledge then the immo loses potency...which is where the sentries come in. In the Artosis replay, had the opponent chosen a different unit composition (ie zealots to storm the ramp) or not become carelessly supply blocked, I doubt the 3stalker build holds up under this pressure because the immortal is late. A late immortal is the same problem with the older 2gate-robo build that was not holding flawless 4gate pressure.

Basically you have to deny deny deny while you build up your own internal force. With the tech advantage of this build your army is stronger albeit slightly slower to develop (3gates vs 4). However, since 4gaters cut probe production your economy stays in better shape.

When I get home I'll attach some replies, but in the mean time this is how things should play out.

• 9 pylon, 2 chronos when it finishes, 13gate scout, 1st gas (standard econ opener).
• your probe arrives in time to see a core go down and it's practically a mirror thus far (obviously you would react differently if you see forge, 2gates, etc).
• Get a second gas immediately after your core starts; thus splitting the mirror paths (the 4gater trains a zealot).
• delay your 3rd pylon
• When your core finishes you need the following 3 things: warpgate tech, a stalker, and a robo I usually opt for robo tech on long rush maps, and choose stalker tech on shorter maps (or if the probe is still in my base).
• chrono the warptech and you'll have it the same time as your opponent
• your probescout has most likely confirmed a 4gate by this time (no second gas and more gates coming) so dont hang around because a stalker is coming out soon. However, it's very important you hide him nearby to proxy a pylon later to stage your own counter
• as you continue to make probes, your robo is warping in, chronoing warptech, and building a sentry as your second unit and putting down another gate
• your first unit should have chased his probe away, hopefully killing it, but dedicated 4gaters leave your base earlier so scout around to see if you can find a careless proxy outside your base, don't venture too far as his stalker/zealot will be on the way soon
• around this time you are starting to cut a few probes because you need to start the immortal asap (the 4gater has already cut his probes at 20-22) but you will end up with ~26
• done correctly and your warpgate tech finishes in time for you to warp in 2 more sentries and you'll have 1 immortal, 3 sentries, and a stalker when you notice the 4gater setting up shop outside your ramp. An aggressive player will try poking your ramp with the zealot/stalkers as his nearest proxy warps in to avoid you sniping it (in range of your stalker/sentries). Since you are behind in unit count your best bet is to just FF him off completely. If you have good micro, isolate the zealot and kill it with your sentries/stalkers out of his stalkers range.
• Depending on his pressure, warp in 3 sentries/stalkers (your 3rd gate should be online).
• your chronod 2nd immortal is here, so just keep up the FFs if you need to and keep warping in stalkers for their range to snipe the proxy and a sentry now and then depending on your energy levels.
• his blind stalkers are going to get blasted by your forces. You should be able to pick off his nearest proxy by this point so you can start splitting his forces since he can't warp over. if you want some zealots to help tank the damage go for it. just keep your immortals alive at all cost
• with his ledge proxy gone, you can start warping zealots at your own proxy near his base forcing him to warp units at home instead of near your ramp
• If he's determined to keep you contained, and you don't have a proxy to pressure his main, you have several options 1) start warping units (zealots) over your ledge to break his contain with your superior army (3 immortals and handful of stalkers/sentries) or 2) during your hold you could put down a robobay and be much closer to a colossus

In either case your economy is much better than his and when you break the contain you can expand to get even more ahead, or directly counter with your tech army to win. Savvy 4gaters who realize the best they can get is a contain will opt to expand in the hopes of catching up on economy, while others attempt a further all-in with a tech choice like voids rays or DTs. As long as you time your counter correctly you'll beat both of these strats with your better tech/econ.

As the battle rages on and you're training immortals and warping in from 3 gates, remember to put down 2 pylons at a time so you don't get supply blocked. Also, as you whittle their army down decide how you want to start teching (blink or colossus). Also be sure to utilize your proxy pylon near his base, or train a warpprism for an immortal drop.

Replays coming

After more testing, here are some important notes on the build: Constant probe production up to pausing slightly to warp in the robo and train your second unit or drop the 3rd gate. At a minimum you'll end up with 26 workers to his 20-22. Delay the 3rd pylon to afford faster robo Watch your supply carefully so that you aren't training a worker when you need to start immortals (~33 supply)

TLDR: gate, gas, core, gas, robo, gate, gate with early sentries and chrono immortals defends a 4gate with better economy and tech to counter for a win

Edit: I found a thread on TL that has been seriously discussing the 1 gas option http://www.teamliquid.net/forum/viewmessage.php?topic_id=191430&currentpage=All