Leveling Overview

Nuclear Throne follows a simple leveling system. Radiation that drops from enemies serves as experience points which will fill the rad meter. Once filled the character will level up, and upon leveling up they may pick one skill/upgrade usually from a pool of four known as mutations.

The player will always start at level 1 at the start of the run, and every consecutive level up will grant a mutation up to level 9. This means that a typical run will have 8 mutations, but a 9th can be gained through Crown of Destiny.

Reaching level 10 is referred to as level "Ultra". It gives choices between mutations that are specific for each character, and will typically give a boost to a character's unique active or passive ability. Any additional rads beyond this point will fill the ultra meter, which are used as additional ammunition for ultra weapons. Rads gained with a full ultra meter will be wasted similar to getting pickups with full health/ammo.

The following table lists how many rads it takes to obtain each level as well as the total rads collected at that point.

Set Basics

Every level up gives a set of four mutations in which the player can select one, from a total pool of 28 mutations normally. Once a mutation is picked it is permanently removed from the pool for that run.

In a vanilla run every set can be considered completely random, as any mutation has equal chances of reappearing. In reality each set is seeded, just that the seed is unknown to the player. There are two exceptions to this, first being weekly challenges which can be replayed any number of times within the time limit. While daily challenges can only be played once, it is on a set seed and players can share information from their own runs for the benefit of others. These both have their own respective pages.