StarCraft II: Legacy of the Void

Several multiplayer game mechanics were modified in Legacy of the Void. Most notably, the resource system was changed in order to encourage aggression and territorial control, and to minimize a lack of action at the beginning of multiplayer games.[11] Changes include decreasing resource quantity and increasing the number of workers spawned at the beginning of the game.[12] Specific changes were also made to the abilities and mechanics of each playable race. The game is still being modified and balanced to this day, resulting in some of the changes described being outdated.

The Protoss no longer have the Photon Overcharge ability. Chrono Boost can apply to multiple structures, and gives a good boost to production for a small amount of time. If used for full duration, it saves 10 seconds on production. The Oracle from Heart of the Swarm now has its Revelation and Envision abilities combined into one. It can now also cast a Stasis Ward, an invisible mine-like structure that, when detonated, traps units in a small radius in stasis, much like the Stasis Field ability from the Arbiter of StarCraft: Brood War. The Warp Prism, the trademark Protoss air transport, now has the ability to pick up units at a longer, safer range, but still must get on point to unload any cargo or deploy its psionic field utilized to warp-in Protoss units. The Carrier now has the ability to launch interceptors at a longer range and safer distance. The Immortal loses its trademark Hardened Shields from HotS and WoL, and instead receives the new "Barrier" ability, which mitigates damage temporarily. As for new units, the Protoss receive the Adept, a Gateway/Warp Gate unit which excels against light-class units like the Terran Marine or Zerg Hydralisk and can use "Psionic Transfer", creating a psionic copy of the unit to which the Adept teleports after a few seconds, favoring hit-and-run tactics. Another new unit is the Disruptor, built from the Robotics Facility and requiring the Robotics Bay. It attacks by discharging a ball of energy which can be player-controlled and directed at the opponent, dealing massive damage. The Disruptor is reminiscent of the Protoss Reaver from Brood War in that precise micromanagement is required to deliver greater damage.

The Terrans remain virtually unaltered of their macro-mechanics inherited from Wings of Liberty, meaning they can still deploy MULEs and Extra Supplies. The Banshee receives a speed upgrade which can be researched at a Tech Lab. The Battlecruiser can now warp instantly to any location, regardless of visibility. The Reaper from Heart of the Swarm gains a grenade-like ability that deals minimal damage, but knocks back and temporarily stuns enemy units. The Widow Mine remains unaltered, except it now has a targeting beam when it fires, which gives further warning to opponents. For new units, the Terrans receive the Cyclone, a Factory-built unit that can lock on and move while firing at air targets only (it can automatically auto-attack ground units), similar to the Protoss Phoenix. Another new Terran unit is the Liberator, which can engage aircraft with its normal area-of-effect attack, but can also transform to deploy a powerful cannon to attack ground targets.

The main alteration to Zerg macro-mechanics is the reduction of extra Larvae produced by Queens per Hatchery, from 4 in HotS/WoL to 3 in Legacy of the Void, and additionally the Spawn Larvae ability can now be used multiple times on Hatcheries to queue Larvae production. For units, the Swarm Host, to accommodate for the returning Brood War Lurker, no longer burrows and has its role altered to a "siege assault" unit, able to spawn its Locust while moving and unburrowed. The Corruptor has its Corruption ability removed and replaced with "Caustic Spray", with which it can target ground buildings endlessly until they are destroyed. The Nydus Worm is altered so that it remains invulnerable while being constructed, removing the opponent's capacity of destroying them before completion with workers. For new units, the Zerg receive the Ravager, an evolution from Roaches (akin to Lurkers from Hydralisks and Banelings from Zerglings) and can use a "Corrosive Bile" special ability that acts like "focused artillery", focusing on a specific location and dealing damage to anything it hits, including air units. Corrosive Bile can also be used to destroy Force Fields.

Some time after the events of Heart of the Swarm, Zeratul searches to unravel the final piece of the Xel'Naga prophecy,[13] which requires him to find the place of Amon's resurrection. To uncover this, Zeratul travels to a Terran installation where he is contacted by Praetor Talis, one of Artanis' commanders. Talis explains that Protoss are captured and experimented upon by the Terrans and requests Zeratul's help. When arriving on the Terran-controlled station, Zeratul encounters Kerrigan and her Swarm, who seek to destroy the facility. Zeratul must race Kerrigan to free the captured Protoss and acquire the location of Amon's resurrection.

After completing his task Zeratul and Talis set off to the planet Atrias, where a Xel'Naga Temple is located. Before Zeratul can enter the temple, he must fight his way through a force of Tal'Darim Protoss, fanatically loyal to Amon. They are led by Highlord Ma'lash, who communes with Amon to receive instructions. Zeratul is successful in defeating the Tal'Darim and enters the temple. Inside he must again fight his way through Tal'Darim forces and destroy a structure known as the "Void Catalyst". This structure appears to allow the Tal'Darim to contact Amon and use its energies to empower them. After the Void Catalyst is destroyed, Zeratul is contacted by what appears to be Tassadar in spirit form, who instructs Zeratul to find the Keystone. Shortly after this, Amon himself attempts to kill Zeratul by collapsing the temple. Talis sacrifices herself and her forces to give Zeratul enough time to escape Amon's wrath. With the last fragment of the prophecy fulfilled, Zeratul sets off to warn Artanis about his findings.

Artanis leads the Golden Armada in an invasion of their Zerg-infested homeworld of Aiur, abandoned since the Brood War six years earlier; Zeratul arrives to warn Artanis of Amon's return, but the invasion proceeds regardless. Amon awakens on Aiur and takes control of the majority of the Protoss race through the Khala, the telepathic bond that unites all emotions for the Khalai and Templar factions of the Protoss. Only Zeratul and the Nerazim, the Dark Templar, remain unaffected as a result of their ritualistic cutting of their nerve cords, which has severed their connection to the Khala. Zeratul and the Nerazim scramble to save as many of the Aiur Protoss as they can by severing their nerve cords, while fending off Amon's Zerg broods and possessed Protoss. Artanis succumbs to Amon's control and attacks Zeratul, who tries to cut off Artanis' nerve cords without harming him. In his final strike, Zeratul severs Artanis' nerve cords, releasing him from Amon's mind-control, but suffers a mortal wound. As Zeratul dies from Artanis' strike, he urges the Hierarch to combat Amon by going to the planet Korhal to recover the Xel'Naga Keystone – the artifact previously used to de-infest Sarah Kerrigan and free her from Amon's control. With the Golden Armada now under Amon's control, Artanis activates the last remaining Protoss Arkship, the Spear of Adun, to serve as his command ship while evacuating the Protoss who have escaped Amon's control.

In the meantime, Amon's forces within all three races, along with hybrids and beings from the Void, begin to wage war in order to extinguish all life from the Koprulu Sector. On Korhal, Artanis arrives in the middle of a Terran battle between Dominion forces and the rogue Moebius Foundation, now under the control of Amon. The Protoss intervene by aiding Jim Raynor and Emperor Valerian Mengsk in defending the planet from the Moebius Foundation and its hybrids before retrieving the artifact.

With the Keystone secured, Artanis undertakes numerous missions to rebuild the Protoss forces. On the Dark Templar homeworld of Shakuras, the warpgate connecting the planet to Aiur has been reactivated and Amon's forces overwhelm the planet. Upon arrival, Artanis helps Matriarch Vorazun, Raszagal's daughter, evacuate the rest of the Dark Templar before obliterating the planet to deny Amon control of it. Artanis also travels to the planet Glacius, a research facility involved in developing advanced Protoss weaponry. The Protoss discover and reawaken an experimental Purifier in stasis, only for Artanis to discover Fenix's consciousness in the Purifier's machine body.

Utilizing data from the Keystone, Artanis is directed to the Xel'Naga homeworld of Ulnar, a planet-sized temple-like structure hidden within a rift which the Protoss had believed could not sustain life. Upon reaching the inner temple grounds, Artanis comes upon Kerrigan battling Amon's hybrid. Artanis enters into a reluctant alliance with Kerrigan after learning that she also fights against Amon. During their investigation, Artanis and Kerrigan learn of the Xel'Naga's origins. Seeking their help in the war, Artanis and Kerrigan find the Xel'Naga dead, slain by Amon and his forces. Amon opens a gateway to the Void, and Kerrigan and Artanis are ambushed by hybrid and spectral forces from the Void. Meanwhile, the Spear of Adun is infiltrated by Alarak, First Ascendant of the Tal'Darim. Vorazun briefly clashes with Alarak, who claims they have a common enemy and that the Protoss Hierarch is in grave danger. Reluctantly, Vorazun sends Protoss forces to coordinates provided by Alarak. Artanis and Kerrigan are rescued by the timely arrival of their forces.

Alarak reveals Amon as a false prophet; the Tal'Darim believe their faith in Amon will be rewarded through their transformation into hybrids, a belief revealed by Alarak as a lie. Seeking vengeance for Amon's betrayal, Alarak proposes a bargain to Artanis: Artanis would help Alarak overthrow Highlord Ma'lash as leader of the Tal'Darim, and Alarak would remove the Tal'Darim from the conflict, depleting Amon's ranks. Artanis reluctantly agrees and helps Alarak complete the Tal'Darim tradition of Rak'Shir combat to overthrow Ma'lash. Alarak declares the Tal'Darim free from Amon's control, and declares vengeance against his former god.

At the behest of Fenix, Artanis seeks the help of the ancient Purifiers despite the misgivings of his advisers. At Cybros, a facility orbiting the forest world of Endion, Artanis fights through waves of Amon's Zerg to awaken the ancient Purifiers, mechanical soldiers programmed with the preserved minds of legendary Protoss warriors. Created by the now-defunct Protoss Conclave, Purifiers were treated as weapons instead of as fellow templar. This resentment came to a head when the Purifiers rebelled and the Purifier program was shut down. With the help of Fenix, Artanis is able to placate their bitterness and convince them to join his forces while standing together as equals.

With the newly united Protoss forces, Artanis stages another invasion of Aiur while the Golden Armada wreaks destruction in other parts of the sector. After destroying Amon's host body, Artanis is successful in temporarily trapping Amon's consciousness in the Keystone. With the brainwashed Daelaam Protoss temporarily freed from Amon's mind control, Artanis urges them to sever their nerve cords to disconnect themselves from the Khala and deny Amon's consciousness an anchor in real space. The Aiur Protoss sever their nerve cords and Amon is banished into the Void. With Aiur reclaimed and the Protoss unified under the Daelaam, the Protoss begin to rebuild, ushering in a new age of prosperity and peace on their home planet.

Some time after Amon's defeat on Aiur, Kerrigan sends a psionic call to Raynor and Artanis, directing them back to Ulnar as a staging ground for an invasion of the Void in order to permanently end Amon's threat. The combined Terran/Zerg/Protoss armada successfully breaches Amon's first line of defense, and Alexei Stukov, the Zerg-infested former vice admiral of the United Earth Directorate, kills a resurrected Duran/Narud, revealed to be a Xel'Naga himself, in retaliation for Duran killing Stukov on Braxis during the Brood War. In the process, Artanis, Kerrigan, and Raynor release an imprisoned Xel'Naga named Ouros. Upon Ouros' release, the three heroes learn he was the one who was using Tassadar's visage to guide them and that in order to maintain the Infinite Cycle, a fellow Xel'Naga has to kill Amon. Only Kerrigan at that point is capable of surviving such an ascension. After merging with Ouros' essence, Kerrigan becomes a Xel'Naga. With the help of the joint armada, Kerrigan kills Amon, ordering the remaining armies to flee as her final attack creates a psychic backlash in the Void.

Two years after Kerrigan's victory over Amon, Emperor Valerian Mengsk and Admiral Matthew Horner have ushered the Terran Dominion into an age of peace and prosperity. Negotiations with the unified Protoss are making progress and the two races are at peace. Raynor reunites with Kerrigan, who appears in her human form, and leaves Mar Sara. He leaves behind his badge, setting aside the final piece of his troubled past, and is never seen again. Meanwhile, Alarak has declined to accept a permanent alliance with the Daelaam, but allows any Tal'Darim a single chance to join them before leaving to find a new homeworld. The Zerg, now under their new queen Zagara, have aggressively reclaimed Char and the surrounding systems as their new homeworld. As peace gradually settles in, life unexpectedly blooms on previously barren and ravaged worlds in the sector.