Weapons designed to penetrate armor, bypassing the added layer of protection completely.
The first video game about Armor penetrators was released in 2011.
MinMax Games has published all these games
See also: shield penetrators
Realistically speaking only radiation weapons would work like this, and even their effectiveness can be reduced. Anything else tends to be far more questionable in how well they will actually perform (the fact that soldiers still bother with personal armor is pretty good proof of this).