Zzoram said:
Learn to apply early pressure like Protoss players do to Terrans in SC1. Use your first Stalker to peck at the wall-in, and keep adding more to the group. Marines can't hit Stalkers from behind the wall, so he'll have to waste considerable money repairing constantly if he doesn't want to die.
no no no! Beware the idea that you can pressure a Terran in the current state, you will just lose units to marauders unless they are straight teching to banshee. Not only do marauders kite stalkers but they straight up counter them in a fair fight.
Didn't mean to jump on you Zzoram but that can be dangerous advice with the new Terran build of straight marauders that is so popular right now, a week ago you could get away with it fine.
General advice:
-Scout early, either your 9 probe or your 10 probe after building the pylon, look specifically for how early his gas is and what buildings are in his base.
-A Terran with an early gas is either reaper or marauder rushing you - in either case you need to tech to a stalker ASAP and build 1 zealot in the mean time to take the hits instead of your probes, also cut probe production if it is slowing down your ability to get a cybernetics core and a single stalker that you place in your mineral line.
-If the Terran is doing a more standard build without an early gas it is absolutely key that you see his rax in his base, if he does not have a rax in his base or he has a slow rax and no gas then you are 100% being proxy rushed, in this case throw down an extra gate ignore the cybernetics/gas and just pump out zealots while a probe from your base finds the proxy buildings.. 2 gates pumping zealots with chrono boost can defeat almost any kind of terran proxy rush.
-In the event of a game lasting past the 4 minute mark (which it should if you're aware of the 2 scenarios I just explained) then you need to keep scouting and reacting to your enemy, rush for a robotics facility (probably with 1 gate if he isn't rushing you) and chrono boost out an observe, send it over to his base to see what he's up to.
-Continue to build gates at this point as 3 gates with the warpgate upgrade and 1 robo facility can safely counter just about any terran build
-If he has a few rax's with tech labs he is going for a bio ball of marine/marauder and later medivacs, in this scenario you need to build an immortal or two along with a bunch of zealots, maybe 1-2 stalker and 1-2 sentry, limiting the amount of stalker/sentry you build throughout the game should allow you to build a robotics bay while making your 1-2 immortal and smoothly transition into colossus. You want to avoid large groups of stalker/immortal since even though they hard counter marauder you will lose to players who know how to use emp, this is why colossus WITH the range upgrade are a much better unit to transition to.
-If he has starports with tech labs, you are in trouble but it can be dealt with. First bring your observer back to your base because nothing is more annoying than stealth banshees, start warping in a mixture of stalkers and sentries from your 3 gates while slapping down a forge, you should now be able to hold off his attack and safely expand while slapping 2 cannons at each of your mineral lines as banshees are a significant investment and he wont have a real ground army for ~2 more minutes (if he chooses to transition at all).
-Remember that when you expand (which you should do ANY time you feel you have ANY kind of advantage, regardless of how small it is) you need to increase your production facilities and add a tech tree, my favorite way of doing this is slapping down another 3-5 warpgates and adding a twilight council/templar archives, this gives you access to an instant army anywhere you want with tier 1, 2, and 3 units. Templars are great for crowd control or using feedback on terran units such as the medivac, banshee, thor, ghost, or battle cruiser. You will end up with a huge amount of spare minerals if you go the templar route which is why having ~10 gates can be a good thing as it allows you to spam down some zealots or also build photon cannons at weak areas of your base (or a new expansion).
The important stuff to remember in PVT is to keep your cool and always be aware of what the Terran player is doing, you should have the advantage if you stay 1 step ahead of him on scouting and use the appropriate counters, sadly some scenarios are just kind of bullshit (terran air on scrap station for example or really good terrans who know how to best use EMP) but you should be able to put up a good fight if you know what you are walking into.