Here is the basic types weakness guide. 1/2 means half 2 means double. All the pokemon types are listed on the left side and the attack types run across the top.
Nrm | Fire | Wtr | Ice | Grs | Elc | Rock | Grd | Fgt | Bug | Pos | Fly | Psy | Gst | |
Normal | 2 | x | ||||||||||||
Fire | 1/2 | 1/2 | 1/2 | 2 | 2 | 1/2 | ||||||||
Water | 1/2 | 1/2 | 1/2 | 2 | 2 | |||||||||
Grass | 2 | 1/2 | 2 | 1/2 | 1/2 | 1/2 | 2 | 2 | 2 | |||||
Electric | 1/2 | 2 | 1/2 | |||||||||||
Ground | 2 | 2 | 2 | x | 1/2 | 1/2 | ||||||||
Fighting | 1/2 | 1/2 | 2 | 2 | ||||||||||
Bug | 2 | 1/2 | 2 | 1/2 | 1/2 | 2 | 2 | |||||||
Poison | 1/2 | 4 | 2 | 1/2 | 2 | 1/2 | 2 | |||||||
Psychic | 1/2 | 2 | 1/2 | 2 | 1/2 | x | ||||||||
Dragon | 1/2 | 2 | 1/2 | 1/2 | 2 |