Tanks

Tanks are entities in Diep.io that can shoot free-moving Bullets, Drones, or Traps. They are controlled either by a player or by AI.

Design
All tanks consist of a body and one or more Barrels. The size and placement of the Barrel(s) depends on the Class of the tank.

Shape

 * Almost all tanks have a circular body.
 * The only exceptions are the Necromancer (a square), and the Mothership (a hexadecagon, a 16-sided polygon).
 * Taking into consideration the dark outline around the tank, this also includes the Smasher (a hexagon), and the Landmine, (an icositetragon, a 24-sided polygon, in the shape of a 12-pointed star). This also includes Auto Smasher, which looks like a Smasher with an Auto Turret.
 * Barrels can appear in many different shapes, sizes and numbers.
 * Barrel shape often determines bullet characteristics; wider Barrels shoot larger Bullets, and longer Barrels have faster Bullet Speed.
 * Normal Bullets, used by most of the tanks, are circular shaped.
 * Some tanks use Drones or Protectors, which are often triangular shaped, but, in the case of Necromancer, can be square shaped.
 * Some tanks use Traps, which are concave hexagons.

Color

 * The color of a tank's body is based on its team's color (ex. blue, red, purple or green ).
 * Your tank is colored blue in FFA, while everyone else's is red.
 * Neutral tanks, like Arena Closers or unclaimed Dominators are always yellow.
 * Some Boss tanks have special colors, such as pink or yellow.
 * Fallen Boss tanks are light grey.
 * Contrary to some depictions, the outlines of tanks and Barrels are a  very dark grey , not pure black.
 * Barrels are always colored dark grey.
 * Your Bullets are blue in FFA, while everyone else's Bullets are red . However, in FFA, a Necromancer's Drones are colored peach / orange.
 * In team Game Modes your Bullet color is determined by your team. Bullets of neutral tanks are yellow (same for Drones).

Movement
All controllable tanks can move their body with the arrow or WASD keys. They can move their Barrel(s), which always points at the cursor, with the mouse. Pressing C will make the tank spin automatically.

Shooting Bullets
To shoot Bullets, a player can press SPACE, or left click with their mouse. Pressing E will enable the tank to fire automatically. However, Smasher and its upgrades (except Auto Smasher) lack the ability to shoot Bullets.

Controlling Drones
For any tank that utilizes controllable Drones, left-clicking (or SPACE) will bring the Drones towards the mouse cursor, while right-clicking (or SHIFT) will repel them away from the cursor. Otherwise, Drones will return to the tank and circle it slowly, unless there is a Polygon, a Boss or another enemy tank nearby.

Other controls
Some tanks have additional controls as well. For example, right-clicking while playing as the Predator will extend its focus in the direction of the mouse.