What is Nature?
Natures are characteristics that subtly influence how a Pokémon's stats grow as it gains experience.
Let's check pokemon Mr.Mime as an example:


Each Pokémon can have a Nature that affects two of its basic stats, boosting one by 10% while decreasing another by 10%. There are 25 different Natures, with various combinations of boosts and decreases.
Some Natures have no effect on stats, boosting and decreasing the same stat. Below you can check all existing natures:
No Change Stats

Special Attack

Attack

Special Attack

Defense

Special Defense

Attack

No Change Stats

Defense

Attack

Defense

Special Attack

Speed

Attack

Special Defense

Defense

Attack

Special Attack

Attack

Special Defense

No Change Stats

Special Attack

Speed

No Change Stats

Speed

Special Attack

No Change Stats

Speed

Defense

Special Defense

Special Attack

Defense

Speed

Defense

Special Defense

Attack

Defense

Speed

Special Defense

Attack

Speed

Special Attack

Special Defense

Special Defense

Speed
