Necromancer

The  is one of the six current Upgrades from the Overseer, and can be selected at Level 45. It may not upgrade any further, as Necromancer is one of the final six upgrades.

Design
The Necromancer is a square with two inactive trapezoid Spawners, on opposite sides. The Necromancer generates Drones only by bumping into Squares or by hitting them with its previously “captured” Square Drones. In FFA it’s hard to say whether a peach colored Drone belongs to a Necromancer or the Summoner (If the Summoner is present in the arena), the only clue to their origin is their behavior ( Summoner squares move like Battleship Drones, while Necromancer Drones move in a cloud)

Technical
When upgrading from Overseer, Drones become weaker, but maximum Drone count is increased by a high amount.

Ability
Initially starting out with no Drones, the Necromancer must bump Squares with its body in order to gain Drones. This “infects” them, darkening their color to a peach tone (or to the player’s team’s color if they are playing in a Team Game Mode). Infecting a Square will not give the player any points. These Drones may then be controlled by the player. These “infected” Square Drones can be used to hit other Squares, which also turns them into Drones. Note that a player must destroy the Square to “capture” it. Also note that Green Squares can also be captured by this tank, but the resulting Drone will not be any different from other Drones. A Green Square drone will give the Necromancer 1,000 XP when the drone is destroyed, in stead of 0.

Without any upgrade points, the Necromancer can control a maximum of 22 Square Drones at any time. However, the player can control an extra 2 Drones for every upgrade point they spend on the Drone Count stat (which replaces the Reload stat), which can be applied up to 7 times for a maximum of 36 controllable Drones.

The Square Drones of the Necromancer, with maximum Drone Health and Drone Damage Stats, have 25 HP and Health Regen to restore health if untouched for some time.

Because of the 12 Polygon limit and the fact that Necromancer Drones are counted as polygons there, the players may only get 12 drones in Sandbox, after which no more Polygons spawn.

Controls
In terms of controls, the Necromancer is basically the same as the Overseer and the Overlord. Pressing E for Auto Fire causes the Drones to follow the cursor without holding left click or space, while holding right click or shift repels them from the cursor. Leaving the mouse unpressed causes them to congregate around the player in a dense cloud and slowly orbit them in a continuous clockwise rotation or attack the nearest Polygons and tanks.

Strategies

 * Strong Against: Individual tanks, Almost slow tanks, Overlords with low Reload, Rammer tank, Boosters, Sniper Branches, Smasher Branches, Skimmer, Battleship
 * Weak Against: Penta Shots, Spread Shots, Octo Tanks, Fighters, Destroyer classes except Skimmer, Overlords with high Reload, and groups of enemies. When low on Drones, weak against everything.

As the Necromancer

 * The Necromancer is one of the hardest tanks to use effectively, due to it lacking the ability to spawn Drones. A high skill level is needed for this tank, but it can easily become one of the best tanks in the game if it is effectively used, surpassing even the Overlord if the player is aware of the Necromancer’s repelling ability.
 * Squares are central to the Necromancer’s ability, so the player should upgrade to the Necromancer where Squares can be found with ease & there are no players to interrupt the collection of Drones. A Necromancer’s Drones are it’s primary offense as well it’s defense, so it is wise to put several points into Drone upgrades.
 * Players should never swarm their Drones forward or just block the enemy’s Bullets with Drones. Both of these strategies will lead to the enemy cutting right through the Drones, leaving the Necromancer defenseless. A better strategy is a player using its Drones to quickly attack and hope that they kill them or injure them so severely that they have to retreat. As soon as players see that their Drone fleet is severely reduced, they should immediately retreat and gather more Drones. Players should make sure to also stay near squares when in battle.
 * Players should play this tank like an Annihilator, not like an Overlord. Necromancers are meant to barge in, claw everything, then regroup and try again. Attacking Trappers and Bullet spammers is not recommended until the player has mastered the Necromancer’s tech and ambush ability first.
 * The Necromancer’s main talent is swift kills; long duels will usually put the Necromancer at a disadvantage. This applies for all tanks, but affects the Necromancer the most since it can lose its Drones permanently. This disadvantage is very small when fighting rammers, since they avoid Drones to ram the player’s hull. Bullet spammers on the other hand, with their massive DPS, will almost always kill the player if the player delays too long.
 * The “claw” is a very common strategy among skilled Necromancers. To perform it, a player must hold their Drones together, then press shift/their right mouse button to repel their Drones and hold their mouse far away from the Drones to keep them in a tight formation. The claw must be tight enough to destroy everything in the area it is sent it in while still being spread far enough apart to kill Bullet spammers. Only three tanks are able to survive and counter this, so it is a good idea to try mastering it in Sandbox.
 * Necromancers should stay away from the Pentagon Nest unless they have teammates to protect them there.
 * A Necromancer holding its cursor right in front of themselves in the direction they are moving is a good defensive strategy. This moves all their Drones into an armor-like formation that completely covers their tank, protecting them from enemy attacks and Body Damage tanks like the Booster. Because of this, using this strategy will make them almost immune to attacks from Invisible enemies.
 * In team game modes they make great support tanks, as they can use their large numbers of Drones to cover teammates while healing or under fire, making them very useful.
 * A way for player to quickly gain Drones is for the player to first infect a few, then go to a relatively undisturbed area with a high concentration of Polygons and send their Drones spreading through it by clicking and holding the right mouse button. If the player waits around ten seconds then call their squares back, they can usually gain almost a maximum number of Drones. Before the player attempts this, they should make sure there are no hostile tanks around because they will be undefended.
 * In 2/4 Teams, an effective (albeit slow and conservative) strategy is to stay within the Team Base and send out all of the player’s Drones along the borders of the base with left click. Because of the sheer amount of Drones and the ability to infect (and thereby resurrect) other Squares, these Drones can continue indefinitely through all but the heaviest enemy fire and destroy every Polygon in their path. The player should be wary of holding shift long enough for the Drones to hit the enemy Base and be destroyed, this is also a bad idea in Maze, since the walls will destroy a large amount of Drones.
 * Despite the annoyance of gathering more Drones from within their Base if they are destroyed, it allows the player to effectively grow even if the entirety of the server is controlled by the enemy team. So long as the the player never leaves itheir Base, they can not die until the server closes.
 * A famous strategy for killing rammer tanks is the “Border Claw.” To perform, players must use the right mouse button to make their Drones scatter along the border of the Arena, then sit idly above the Drones. If a rammer tank decides to attack the player, the Necromancer can then summon their Drones back and surround the rammer.
 * Battleships can potentially have more Drones at a time then Necromancer’s do, but their Drones are much, much weaker. Therefore, Battleships should be easy kills for Necromancers.

Against the Necromancer

 * Necromancers can defeat a wide variety of tanks, but it’s not overly dangerous against some high rate of fire tanks, such as the Penta Shot or Spread Shot. All others should attempt to avoid the Necromancer.
 * Necromancers cannot target fast moving tanks such as Boosters and Smashers. Unless the Necromancer is skilled, the player can just keep on running around it while killing its Drones (this works especially well with a Fighter). If the Necromancer does not engage when the player applies this tactic, the player should disengage and go somewhere else. Skilled Necromancers will keep themselves shrouded in their Drones and retreat, and they will try to surround and dispatch of the player should they get too close. It is not recommended to use this strategy with any other tank besides the Fighter.
 * Necromancer Drones are somewhat weak, so a Bullet-build Destroyer, Hybrid or Annihilator’s large Bullets may destroy many of the player’s Drones in only a few hits; once all of the Drones are destroyed, players can use their recoil to boost towards the now-helpless Necromancer and kill it in a single hit.
 * Skilled Necromancers know not to do this, they will instead keep their drones spread out, this allows them to hit an enemy from all angles while keeping their drones safe. If this happens, the player should either leave or use the Destroyer’s recoil to get close and kill, beware that they will attempt to predict the player’s movements and may kill them, the player should try to be unpredictable and chaotic.
 * Another useful strategy for the player is to catch inexperienced players who are attempting to learn how to use this tank. Because of its fame and difficulty to master, around a third of Necromancer players will not be able to properly utilize this tank and are easy prey. If they have a score of 100K or above, however, it is advisable for the player to use the tanks that are listed as strong against the Necromancer.
 * The player could also try to team against and stalk the Necromancer. They should keep in mind however, that this may result in a great deal of the players in the server targeting them, as it has been proved that many Diep.io players hate teamers in FFA.
 * On rare occasions, the Octo Tank is an effective counter against the Necromancer. If the Octo Tank is low on health, they would probably die if a Necromancer swarms their Drones at them. If the Octo Tank has low Bullet Speed however, the bullet wall could be impermeable to the Necromancer Drones.

History

 * Necromancer Drones used to display Health Bars, but they were later removed.
 * In earlier versions of the game, Drones could spawn very slowly from the Necromancer’s spawners, and the ‘Reload’ stat could slightly decrease that Reload time. This feature was removed because it is somewhat pointless as it would take hours to amass an army using this feature.
 * As of June 13th, the Reload was changed to Drone Count. The Drone cap with zero Drone Count was then 20 and the full Drone count was then 34.
 * As of October 23, the Necromancers’ Drone Count was buffed; the minimum was increased from 20 to 22, while the maximum was increased from 34 to 36 in a secret update.
 * On July 30th, the Necromancer was balanced, decreasing its Drone Health but increasing its Drone Speed.
 * On October 23rd, the Necromancer’s Drone Speed was increased in a secret update.

Trivia

 * The Necromancer is named after, a type of wizard known for raising and controlling the dead. This references the Necromancer’s ability to control Squares when they’re “killed” by the Necromancer.
 * This is the very first tank added to the game after the Changelog was released. The Necromancer was added in the May 18th update in the same patch the Changelog itself was added.
 * It is the first playable tank with a square shaped body, the only other square-shaped tanks being the Factory and the boss, Summoner (which is not playable, even in the Sandbox game mode).
 * It is also the only tank with inactive Spawners. Their only purpose is to show that it’s a Drone Tank.
 * It is also one of the tanks that have had some of their functions removed (spawning squares).
 * Some players (especially on ) refer to the Necromancer’s Drones as “Sunchips,” as they resemble Sun Chips.
 * Another common term is “Necro,” a shortened form of “Necromancer”.
 * If you are Triple Twin in Sandbox, and have bullets in-game when you switch to Necromancer with the / key, the Squares hit by your Triple Twin bullets will turn into your Drones.

Bugs
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Unpatched Bugs
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 * Capturing all Squares in the Sandbox arena alone as a Necromancer will prevent any more Polygons from spawning until any of the squares are destroyed. A possible reason for this is that the captured squares are still counted as Polygons, and only twelve Polygons can spawn in the Sandbox arena when there is only one player.