Grass

Grass pressures Water and Ground, but Fire, Ice, Poison and Flying remain common answers.

Look up the type matchup matrix View defense in the matrix

Two-way summary

Dealt by Grass

×2 Increased (×2): Water
Ground
Rock
×½ Reduced (×½): Fire
Grass
Poison
Flying
Bug
Dragon
Steel
×1 Neutral (×1): 8 neutral types — open the full table below

Taken by Grass

×2 Increased (×2): Fire
Ice
Poison
Flying
Bug
×½ Reduced (×½): Water
Electric
Grass
Ground
×1 Neutral (×1): 9 neutral types — open the full table below

×2 Increased (×2)
×1 Neutral (×1)
×½ Reduced (×½)

How does the second type change things?

Normal moves

Gogoat

Gogoat

Grass

Multiplier on Grass: ×1
Result: ×1

Decidueye

Decidueye

Multiplier on Grass: ×1
Multiplier on Ghost: ×0
Result: ×0