Traits

Traits are split between positive ones, which cost points and help your character, and negative ones, which give you points and hinder your character. The right selection of traits can mean the difference between a living survivor and a rotting corpse.

Several starting professions also grant you special profession traits which are based on the characters' career before the Cataclysm and grant you access to equipment and places that you might not otherwise be able to attain among other bonuses.

Some starting scenarios in 0.C (Cooper) also give you different choices of starting traits. For example in the Challenge-Lab scenario, you can choose several mutations, like for example Gills, as a starting mutation. This because your character was experimented upon before the apocalypse. Or, you might even be a clone of ... something. These starting mutations count as traits, so they cannot be removed with purifier, and do not count for threshold mutations.

Changing starting traits

You cannot change starting traits normally, and purifier will try to give them back to you. But if you really want to change your starting traits you can use the mutate option of the debug menu.