Once you’ve learned how to send an early scout off to collect intel, understanding the information received is the next step to your fundamental skills of scouting. Once accomplished, you can assertively and effectively build according to your given situation.
There are several common ways to deduce your observation based on your scouting in the early game. If not a standard build, your opponent may then lean towards an early aggression called a rush, or a high economic build. Although there are many types and styles of rushes, let’s look at the most common ones.
How to spot a rush: Once your early scout reaches the enemy base, be attentive to your opponent’s building types and any units. You can do this by speculating some particular buildings or the lack of standard buildings you’d expect in the base.
If against Terran, spotting an early refinery is the main icon to a reaper build, even if you do not spot the necessary tech lab annexed to a barracks. If you find a factory with a reactor, prepare for hellion attacks which are extremely powerful in numbers against your harvesters. An early Starport with a tech lab spells banshees that specialize in air to ground harassment with optional cloaking.
If against Protoss, discovering several (3-5) gateways, often with no assimilator, is likely a zealot rush of six or more at a time. If you find a forge but no gateways, this should tell you the player is contemplating a cannon rush, which means an aggressive wall-in build of photon cannons in your base. An early Stargate may indicate a phoenix harass or void ray aggression.
If against Zerg, a quick 6-8 spawning pool will reveal to you an initial 4-6 zergling rush, and then in larger numbers. Zerglings, often with speed upgrade, are used for rushing, along with scouting purposes. If they continue with the rush for a long duration, most likely they are transitioning into a mutalisk build. The spawning pool also allows spine crawlers rushes, which is a similar concept to the Protoss cannon rush.
Search your opponent’s base for buildings positioned on the edges or in unexpected places. It is very common for skilled players to hide their tech buildings away from the central point of their base, sometimes even beyond their safety perimeters. However, when you do not see standard buildings in their base at all, even after a thorough search, a proxy build is in play, where the enemy is secretly building certain units for a surprise attack. Proxy plays are common with reapers, zealots, and hellions, less so with air units. Be alert and prepare for further scouting. Otherwise prepare your defense.
What about players who are rarely attacking? This could mean they are going for an economic build to boost their late game. Watch them for any early expansion. Terrans may build their early command center inside their base to transport it later on. Also speculate how many harvesters they have in their base. A large saturation of harvesters indicates an aggressive economic build, which means to your advantage that they cannot afford a large army size during their economic investment.
Zerg players are more likely to expand further away from their main, since hatcheries are comparatively inexpensive to build. Remember that the plays mentioned above are common but are merely part of a pool of tactics. Your opponent may quickly make a transition into other tactics according to their intel on your gameplay.