Armour can be layered, but only in a certain way. Armour is listed as being “under-armour”, “over-armour” or “exclusive-Armour”. Under-Armour and Over-Armour can be worn together and stack fully (per location), other combinations of armour can not been worn together; if other combinations of armour are worn together due to special circumstances, only the best armour counts (if the armour has disadvantages, all of the count).

Under-Armour is clothing or otherwise worn close to the skin (clothes, jumpsuits, concealed armour).
Over-Armour is worn over clothing (vests, overcoats).
Exclusive-Armour is heavy armour, generally worn as complete suits (Bulldozer suit)

Armoured Jumpsuit
Armoured business suit
Armoured casual clothing
Light vest
Light vest with with trauma plates
Ballistic mask

Heavy vest
Heavy vest with trauma plates
Armoured jacket
Armoured jacket with trauma plates
Armoured overcoat
Shell Armour
Partial Helmet

Bulldozer suit
Complete Helmet


Shadowrun ORE badgerish