Used to support zealots in light of the protoss race's diminishing population, sentries are protoss combat drones. Sentries employ a disruption beam to attack their enemies, and offer protection through guardian shields. Sentries are able to move and levitate off of the ground through generators that create pockets of zero gravity.
Sentries can also project force field barriers to stall or split up opposing forces. This is done by turning bursts of energy into a small, impenetrable barrier to hinder, block, or funnel the advance of enemy troops. While creatures or machines of prodigious size can shatter the cohesion of these translucent force fields, ordinary soldiers and vehicles become fodder to protoss ranged weapons.
Sentries an protect allies via guardian shields, created by weaving light into a semi-solid state. Through this, the sentry can surround itself with an area-encompassing shield to safeguard protoss ground forces. Projectiles or energy blasts that penetrate the field lose some of their kinetic or thermal energy, and part of their effectiveness. Due to its considerable coverage radius, the guardian shield is not powerful enough to make much of a difference against larger types of ordnance.
Sentries also have the ability to create hallucinatory images through an in-built holo-projector. These holograms can draw enemy fire while a real protoss strike force maneuvers into position to deliver the killing blow. These hallucinations are composed of solid light and are three-dimensional, able to mimic protoss warriors, vehicles, and constructs. Each replica, while limited in duration, is able to withstand some degree of punishment. The purpose of these lifelike images is twofold: making the enemies of the protoss believe they're fighting a much larger force than anticipated, and protecting protoss lives.
By 2506, some sentries were outfitted with portable shield batteries to better sustain the lives of protoss warriors in battle.
After the End War, as part of an artistic movement calling back to the Golden Age of Expansion, some sentries were redesigned in the ancient styles of the era to complement vessels with longer histories.
The sentry has a beam which does continuous damage to one target. Their high gas cost relative to their low HP and attack power, delgates sentries as support units for other troops rather than frontline fighters.
Sentries produce false copies of units to distract opponents. Duplicates have the same number of hit points as the original but take double the damage. The number of hallucinations created depends on the unit: gateway units spawn in twos, probes in fours, and all other units spawn one.
In Whispers of Oblivion, the sentry gains a Shield Recharge ability; Previously available on the shield battery buildings, it recharges the shields of nearby protoss units at an energy cost. The sentry cannot attack while using Shield Recharge. In the Legacy of the Void campaign, the sentry lacks Force Field. The Aiur sentry can use Double Shield Recharge, allowing them to restore shields to two units.
The player may choose the energizer or havoc as sentry variants in the Legacy of the Void campaign. The sentry acts as a purely defensive support unit between Guardian Shield and Double Shield Restore, whereas the energizer and havoc can support the player's armies with more offensive-based abilities, and all three are highly viable.
Sentries can use Force Field to isolate enemy workers, preventing them from escaping their onslaught.
Force Field also proves to be very effective for splitting forces or preventing them from passing through choke points. Melee units may be blocked with force fields and attacked with ranged units. Force fields can be broken by Massive units and ravager corrosive biles.
Guardian Shield is most effective against attackers with low base damage: marines and mutalisks. Guardian Shield protects all ground and air units positioned over the horizontal circumference of the shield (where the shield joins the ground), even if a protected air unit is not visually within the "bubble" of the shield. However, the shield is centralized around the sentry, and units moving outside its area of effect no longer gain its benefits. This means that Guardian Shield is best used by keeping the sentry close to the rest of the player's forces. If the sentry is destroyed, the effects of Guardian Shield will instantly end.
The table shows the effective health for a defender protected by Guardian Shield. The figure assumes the defender has 1 base armor (as is the case with most protoss units), and defender and attacker both have 1 defense and attack upgrade. For example, the defender lasts 66% longer against marines if protected by guardian shield.
The comparisons vary only 0-2% assuming attack and defense upgrade levels remain evenly matched.
The Guardian Shield bonus is applied after the immortal's Hardened Shield. Therefore, effective health of an immortal protected by Guardian Shield is at least 125% (higher if the attacker deals <10 damage before the Guardian Shield bonus is applied).
↑Well since you guys are so intently asking :) Yes, the Nullifier is known as the Disruptor now. Didn't want to bombard you guys with too many name changes at a time. There is still possibility of name changes moving forward as well. Karune. 2009-05-26. Nighthawk+HSM vs Mutalisk. Battle.net StarCraft II General Discussion Forum. Accessed 2009-05-26.
↑Only changes are balance changes, which will still continue to change. Otherwise besides that, the abilities are still the same.
Hallucination still does not work on Carriers, Motherships, Dark Templars, and Observers. I'll have to get back to ya on the lore side :) maybe get them to post up a website update on that.
The Sentry's weapon hits one target at a time, doing damage as long as the enemy is targeted. Karune. 2009-03-16. Karune: Has the Dark Pylon changed?Battle.net StarCraft II General Discussion Forum. Accessed 2009-03-16.
In one of our Battle Report considered replays, I have actually seen 2-3 Nullifiers brought straight into the enemy resource line, then all exits force fielded so the enemy drones couldn't get out, and the Nullifiers pretty much killed a large amount of them easily since they get bonus biological damage. Karune. 2009-05-01. Worker harassment with Nullifiers. Battle.net StarCraft II General Discussion Forum. Accessed 2009-05-01.
↑Dustin Browder, Robert Simpson, Yeon-Ho Lee, David Kim. 2009-06-22. Battle Report (3). Blizzard Entertainment. Accessed 2009-06-22.