The siege tank push, an old favorite from StarCraft, makes its return. Experienced terran players from the previous installment already have it down to a science, but, if you're new to the Koprulu Sector, here's how it works.

Siege tanks deal massive amounts of damage in siege mode, however, their firing range is larger than their field of view suggests. To fully utilize their potential for destruction, you will need to "spot" for them, just like it is done in real military engagements.

First head towards the enemy, ideally with a forward scout so you don't run into any ambushes. Once you're near a potential combat zone, stop the tanks and put them in siege mode. Send your spotters in to reveal the enemy and have your tanks take care of the rest. When the coast is clear, return to tank mode and move forward until you find new targets. 

Leap Frogging is an alternate, safer way to move your tanks. First, get close to the combat zone, separate your tanks (ideally, splash damage from enemy attacks, or your own, should never hit more than one of your tanks) and set them into siege mode. Send in a spotter to find targets, or to confirm that the area is clear, then take one or two tanks from the back of your formation, return them to tank mode and place them in front of the closest tank that is currently firing at the enemy. The premise is to always have tanks in siege mode firing at the enemy and covering your advance. Just make sure you don't delay too much between "leaps", as the enemy might try to catch you while you are moving, or send air units to counter your assault.

Cloaked banshees and vikings are good options to use as spotters (the latter is cheaper to produce and quicker to get to), however, in a pinch you can go with almost anything, like: structures that can lift-off, scanner sweeps, marines, etc. During a stand-off between two tank lines be sure to save as many scans as possible, as both you and your opponent will be attempting to deny spotting. Scans may be your only option, especially if your opponent’s tanks are on the move.

• Bring SCVs to repair your siege tanks.
• Build missile turrets to provide detection and anti-air support for your pushes.
• It’s dangerous for your tanks to go alone. Take support with you. Marines and marauders make excellent backup for cheap and are extremely mobile, allowing you to get the drop on your opponent. However, hellions and Thors are also great support units if you desire a more powerful and less mobile army – especially as all of those units can be upgraded at once.
• Almost as important as the ground battle is the air battle. Whoever controls the skies will be able to spot for their tanks. Once your tank army is sufficiently strong, immediately start production of vikings, ravens, and banshees. During a huge standoff, a rapid air switch could turn the tide of battle dramatically.

A marine spots for a tank so it can fire on destructible rocks, opening up a path to an expansion.	Vikings spot for siege tanks across a ravine. SCVs are ready to repair.
A missile turret defends the siege tanks against air attacks. A Medivac is ready to heal the SCVs on repair duty.	Missile turrets, vikings and scanner sweeps support this siege tank push.
Two vikings spot for siege tanks firing upon an enemy Command Center.	Siege tanks backed up by Thors and hellions.
	Here's the decisive blow against a zerg base.

Counters
Counters to these units come in the form of large numbers of air units with anti-ground attacks, light melee units with speed upgrades, attacks from different sides, and catching the siege tanks while they are moving in tank mode.  No amount of brute force will allow you to muscle your way through a well-positioned tank line, so don’t try. Focus on taking advantage of the tank army’s biggest drawback – their lack of mobility.