How do players customize their army in the single-player campaign of Wings of Liberty?
The campaign offers players different ways to customize their armies to suit their playing style and better tackle the challenges within the missions. Credits earned from completing missions can be used to buy the services of mercenary units that players can deploy in battle. Mercenaries are more powerful versions of standard units in the game; for example, KelMorian mercenary marines have higher armor and damage output than a regular marine. Any skilled mercenaries that players opt to unlock can be built from the merc haven structure within each mission. Additionally, players can opt to buy campaign-only technology upgrades for their units. Examples of upgrades that might be available for purchase include improved bunkers with gun turrets and upgraded flamethrowers that allow firebats to attack a wider radius.
