Tiers

Tiers separate tank classes, organizing them by the characteristics of their barrel(s).

These tiers are represented in the Class Tree, shown to the right, which is a series of concentric rings containing every class in the game. It can be displayed in-game by pressing the Y key. In the direct center of the Class Tree is Tier 1, or Level 1. The first ring contains Tier 2 (Level 15) tanks, the second ring contains Tier 3 (Level 30) tanks, and the outermost ring contains Tier 4 (Level 45) tanks. Areas shaded black on the tree indicate an unavailable upgrade in that tier.

Interestingly, there is a recurring pattern of colors in the upgrade selection menu and the Class Tree. The first tank will always have a  light blue  background. The second will be  green . The third will be  red . The fourth will be  yellow , and the fifth will be  dark blue . Regardless of speculation, these colors do not seem to represent anything other than a simple order pattern to more easily discern tanks apart when quickly selecting an upgrade.

Tier 1: Level 1
All players begin their journey as a Level 1, Tier 1 Tank, a balanced tank with no base stat buffs or nerfs.

Tier 2: Level 15
Upon reaching Level 15, the player may choose to upgrade to one of these Tier 2 specializations:

Tier 3: Level 30
Upon reaching Level 30, the player may choose to upgrade to one of these Tier 3 specializations:

Tank Upgrades
Note: This requires players to stay as a Basic Tank until at least Level 30.

Tier 4: Level 45
Upon reaching Level 45, the player may select one of these Tier 4 specializations. This is the final tier that most tanks are able to legitimately reach.

Machine Gun Upgrades
Note: This requires players to stay as a Machine Gun until Level 45.

Removed Upgrades
These classes existed at one point in the game, but have since been replaced or removed altogether.

Trivia

 * All Tier 4 tanks are at least 126 pixels wide, and at most 175.
 * There is a running theory that the background color of the upgrade icon corresponds to the base stat debuff it gets, as it typically matches the color of the respective stat bar.
 * There are several issues with this:
 * If the background color depended on the tank's stat debuff, there wouldn't be color variants, as seen in the Overtrapper, Auto Gunner, Streamliner, and Battleship, for example.
 * The stat debuffs aren't necessarily true; for instance, the Battleship may have a dark blue background, but with its notoriously fast drones, it certainly doesn't get a debuff to bullet speed.
 * In general, the theory can easily be debunked with simple Sandbox testing.
 * Acquiring level 45 requires you to get 23,536 experience.
 * In Free For All and Team DM, this is equates to:
 * 2354 Squares
 * 942 Triangles
 * 182 Pentagons
 * 8 Alpha Pentagons
 * 1 Boss