Stealth Surprise

When starting off, use the regular routine. Make sure you've got minerals, start buildings gateways, defense and all that other stuff. About mid game, build a robofac (robotics facility) and get reavers. While you're doing that, work on getting Dark Templars. To add an extra bang, get some arbiters. But that usually takes a lot of time. Once you're ready, build 8-12, or 4 if you're low, reavers. Make sure they are in increments of 4. Load them with scarabs, then load them onto shuttles. For the amount of reavers you build, also build Dark Templars. Load them onto shuttles as well. If you want, take along a couple scouts. By now, you should know where your enemy is, and if you can, send a scout to examine their base. Find a weak spot to the edges of their mining facility, or where most of the miners are. Send your shuttles there, but make sure you aren't spotted. If it helps, send in an shuttle to see if they can spot you. When you're sure they can't see you, drop your units down and HOLD POSITION. Also, send a few scouts and maybe an observer. You can't afford to have your units wandering off and getting discovered, so make sure you've held position. If you have an arbiter, have it at the edge of the base so it won't be killed but it cloaks your units. When this is done, tell your reavers to hold position at the edge of the base, and send your DTs to attack the miners. Do NOT attack anything else. When you sense a large force coming in to detect and kill your people, run back to your little camp and kill off all the units that come, with your awaiting reavers and scouts. That'll freak out the enemy. Most people send their WHOLE army to kill your people, but it usually doesn't work because you've set up a good defense, with the cloaking and everything, while they only have a horde of people rushing in. Try and kill the detectors first. After this is done, either use the remaining units to destroy the foundation of the base, or signal your allies! to enter through the front, now that the enemy is centered towards killing the back. Although this is not the fastest tactic, it provides for a good scare, and because of the way it screws up your opponent, it'll provide some good time for you to get ahead economically and unit wise. Good luck with the killing!