This article is for the Multiplayer version of this unit, for the Wings of Liberty Single Player version see: Viking (Wings of Liberty Campaign).
The Viking is an anti-air fighter with the ability to transform into an assault walker (the transformation taking four in-game seconds). The Viking is best utilized when supported by units which can protect the vikings from anti-air attacks from the ground. They are best suited for taking down strong, hard-hitting air units such as Void Rays, Corruptors, Tempests, but do not fare as well against lighter and faster units such as the Mutalisk or Phoenix. Vikings are produced from a Starport (with or without a reactor) and are generally produced in a set number as opposed to continuous production, in order to cost-effectively eliminate enemy air units without overspending resources which could be spent elsewhere.
With a range of 9 in fighter mode, Vikings greatly benefit from proper micromanagement; taking minimal fire from enemy air units while dealing damage or forcing a retreat/relinquishing air superiority. However the assault mode has not seen much use in the current state of the game due to its relatively lackluster damage for their cost.
A notable trick to use when having a number of Vikings is to gather them all at once to one location, which will make them stack onto each other. This will make focus firing much easier and can sometimes confuse an opposing player by making it difficult for them to determine the Viking count. Being stacked like this will make the Vikings very vulnerable to area-of-effect and air splash damage, though.
Note that the Viking always benefits from Ship Weapons upgrade, even in Assault Mode.
The Viking is considered an aerial unit during the full three seconds of transformation. This makes it quite good at hit and run tactics against ground units that can't hit air, as the Viking can liftoff as soon as they are in danger. The same cannot be said about fighting against air units that can't hit ground, as the Vikings will get pelted while they are trying to land.
Because of this, it is actually very dangerous to keep your Vikings on the ground when the opponent has mobile anti-air units: If the opponent flies in his units, your Vikings will either have to stay on the ground, vulnerable to land units, or liftoff, taking a beating during the transformation.
Vikings are mainly useful for infantry support, as they can take out Colossi from a long range. They can also be used to deter Protoss air units, as Vikings out-range Void Rays and Phoenixes. On an equal supply basis, Vikings will be able to take out Void Rays and without micro will go relatively even against Phoenixes and Carriers.
However, Vikings are primarily used to kill Colossi. The number of Vikings to get should depend on the number of Colossi your opponent has. However, you may want to get enough Vikings to take down Colossi in X number of shots.
Assuming no upgrades, Vikings deal 10 (+4 armored) x2 damage per attack to air. Therefore it takes 5 attacks to almost deplete their shields (140 damage). After that they deal 13 x2 damage to the hull per attack (colossi naturally have 1 armor). 6 attacks will deplete their shields and deal 16 damage to the hull. After that it takes 8 shots to deplete their hull health (184 remaining, 26 damage per shot), for a total of 14 shots.
To 3-shot colossus, therefore, you need 5 Vikings.
To 2-shot them, you need 7 Vikings.
To 1-shot them, you need 14.
In TvT, they are used to hold off the opponent's Vikings, Banshee attacks or Battlecruisers. TvT often revolves around getting Siege Tanks and Vikings very early on. While the Tanks do the most of the damage, the Vikings give increased sight so that the Tanks can utilize their full range.
Air dominance is a very important aspect of TvT, as whoever has control of the air will get both the range-bonus for his Tanks, as well as the ability to safely mix Banshees and other air units. In the early-mid game they can also be used for harassing the opponent's mineral line, and in some cases they can be well used as a part of the Terran's ground army. Landing them on top of an opponent's sieged Tanks is also a popular technique. Another option is to land them on unreachable cliffs, to fire at troops underneath them, especially when the enemy doesn't have air units providing sight.
Vikings are often a key aspect of TvT all game long as there is no clear counter for it. Thors can be used to keep Vikings at bay, but as Thors deal low damage against non-light air units, they don't kill Vikings very easily. Battlecruisers can be a viable option in the late game, but as Vikings have longer range, are cheaper and faster to build, Battlecruisers (especially without Yamato Cannon) do not trade against them cost-effectively.
Vikings can play both harassing and support roles in TvZ. Apart from scouting, small numbers of Vikings can be used to kill off Overlords to deny map control. Since Overlords are armored, Vikings get an extra attack bonus while sniping Overlords.
Vikings aren't too cost effective against Mutalisks, but when protected with turrets, thors and/or ravens, they can be used as a deterrent against Mutalisk harass, due to their long range.
In the late-game, Vikings are very effective against Corruptors and a hard counter to Brood Lords. However when Brood Lords are supported by Corruptors and Infestors care must be taken because exposed Vikings can be caught by Fungal Growth. Therefore to trade cost-efficiently the Vikings should be spread out to reduce the splash damage. Additionally, Kiting helps to fight Corruptors due to the Viking's superior range.
Viking's quotes (video and sound) - YouTube video.
|Patch 1 (version 0.3.0.14093)|
|Patch 6 (version 0.8.0.14593)|
|Patch 14 (version 0.16.0.15580)|
Ground damage decreased from 14 to 12.
Lost Viking - Arcade minigame playable in the single player Wings of Liberty campaign.