This site has not yet been updated to reflect the changes in Reborn v19.5. It still only reflects the state of the game as of v19.16.

Harden

Damage class	Status	Type	NORMAL	Target	Self
Power	---	Accuracy	---	PP	30
Priority	0	Additional effect chance			0%
Additional effect description		Increases user's Defense by 1 stage.

In-game description

The user stiffens all the muscles in their body to raise their Defense stat.

Pokémon that learn it

Pokémon	Methods
Metapod	Evolution
Metapod	Level 1
Kakuna	Evolution
Kakuna	Level 1
Grimer (Normal Form)	Level 4
Grimer (Alolan Form)	Level 4
Muk (Normal Form)	Level 1
Muk (Normal Form)	Level 4
Muk (Alolan Form)	Level 1
Muk (Alolan Form)	Level 4
Muk (PULSE Form)	Level 1
Muk (PULSE Form)	Level 4
Onix	Level 1
Krabby	Level 11
Kingler	Level 11
Staryu	Level 1
Pinsir	Level 11
Pinsir (Mega Form)	Level 11
Kabuto	Level 1
Kabutops	Level 1
Sudowoodo	Egg move
Gligar	Level 7
Steelix	Level 1
Steelix (Mega Form)	Level 1
Steelix (Gargantuan Form)	Level 1
Qwilfish	Level 9
Heracross	Egg move
Heracross (Mega Form)	Egg move
Slugma	Level 13
Magcargo	Level 13
Corsola	Level 1
Silcoon	Evolution
Cascoon	Evolution
Seedot	Level 3
Nuzleaf	Level 3
Nincada	Level 1
Ninjask	Level 1
Shedinja	Level 1
Nosepass	Level 4
Aron	Level 1
Lairon	Level 1
Aggron	Level 1
Aggron (Mega Form)	Level 1
Lunatone	Level 1
Solrock	Level 1
Corphish	Level 5
Crawdaunt	Level 1
Crawdaunt	Level 5
Baltoy	Level 1
Claydol	Level 1
Anorith	Level 1
Armaldo	Level 1
Relicanth	Level 1
Wormadam (Sandy Cloak Form)	Level 29
Shellos (West Sea Form)	Level 4
Shellos (East Sea Form)	Level 4
Gastrodon (West Sea Form)	Level 1
Gastrodon (West Sea Form)	Level 4
Gastrodon (East Sea Form)	Level 1
Gastrodon (East Sea Form)	Level 4
Bonsly	Egg move
Gliscor	Level 1
Gliscor	Level 7
Roggenrola	Level 4
Boldore	Level 1
Boldore	Level 4
Gigalith	Level 1
Gigalith	Level 4
Vanillite	Level 4
Vanillish	Level 1
Vanillish	Level 4
Vanilluxe	Level 1
Vanilluxe	Level 4
Ferroseed	Level 1
Ferrothorn	Level 1
Axew	Egg move
Larvesta	Egg move
Spewpa	Level 1
Carbink	Level 1
Bergmite	Level 1
Avalugg	Level 1
Avalugg (PULSE Form)	Level 1
Diancie	Level 1
Diancie (Mega Form)	Level 1
Grubbin	Egg move
Wimpod	Egg move
Sandygast	Level 1
Palossand	Level 1
Pyukumuku	Level 1
Buzzwole	Level 1
Celesteela	Level 1