Weak Armor

Physical attacks to the Pokémon lower its Defense stat but sharply raise its Speed stat.

Level-Up

The following Pokémon can equip this ability after reaching a certain level.
# Pokémon Type Level
211 Roggenrola 1
212 Boldore 1
308 Skarmory
90
318 Omanyte
16
319 Omastar
16
320 Kabuto
16
321 Kabutops
16
245 Heracross
90
297 Dwebble
18
298 Crustle
18
77 Trilopod
25
78 Nautilazer
25
120 Garbodor 1
257 Kakuna
85
344 Qwilfish
30
345 Overqwil
30
366 Exeggcute
18
438 Chinsumuri
18
439 Lansumuri
18
322 Glastro
1
323 Glastle
1

Natural Ability

The following Pokémon can have this ability when you find them in the wild.
# Pokémon Type
211 Roggenrola
212 Boldore
120 Garbodor
322 Glastro
323 Glastle

Hidden Ability

The following Pokémon can have this ability as their hidden ability.
# Pokémon Type
308 Skarmory
318 Omanyte
319 Omastar
320 Kabuto
321 Kabutops
297 Dwebble
298 Crustle
77 Trilopod

Tutored Ability

The following Pokémon can be taught this ability.
# Pokémon Type
159 Excabrute
211 Roggenrola
212 Boldore
213 Gigalith
57 Pteroret
228 Spruvyne
229 Quervyne
230 Sampervyne
317 Armaldo
101 Empoleon
394 Cofagrigus
216 Aron
217 Lairon
218 Aggron
308 Skarmory
318 Omanyte
319 Omastar
320 Kabuto
321 Kabutops
188 Applin
189 Flapple
190 Appletun
191 Dipplin
192 Hydrapple
97 Shellder
98 Cloyster
245 Heracross
297 Dwebble
298 Crustle
145 Wimpod
146 Golisopod
39 Krabby
40 Kingler
77 Trilopod
78 Nautilazer
119 Trubbish
120 Garbodor
254 Metapod
255 Butterfree
257 Kakuna
258 Beedrill
344 Qwilfish
345 Overqwil
366 Exeggcute
368 Exeggutor
367 Exegutower
401 Omnibyte
402 Omniczar
341 Pinsir
371 Carbink
438 Chinsumuri
439 Lansumuri
322 Glastro
323 Glastle
273 Monophlion
274 Dicephlion
275 Ydraphlion
387 Ladstone
388 Marbelle
389 Elegarden
??? Phantump
??? Trevenant
??? Cranisect
??? Skultulant