we were a bit uncertain exactly ourselves, so we started looking up facts, rather than guessing fully.

[url=https://www.quora.com/How-did-soldiers-die-while-wearing-a-suit-of-armor-or-other-historical-armor]Some people who know more than we do about this explaining[/url]

Going from what we read there, any sort of edged weapon (axe, sword, etc) are pretty useless against good, quality plate armor. You don't cut through the plate. Spiked or really pointy weapons have a better chance (thrust spears, spike end of a poleaxe, ballistae, heavy crossbows, longbow arrows), but you don't cut the plate with anything non-magical, and since Formaroth lacks enchanted weapons, that's the relevant physics, we think.

A blunt instrument like a maul or a mace might dent the armor and make it rather uncomfortable to wear. Maybe break a few ribs or other bones, but probably won't instantly kill the way a spiked weapon would. Plate armor is designed with curves that make edged blows slide off. Even a spiked weapon needs a lot of force to get around this.

The classic "boob" plate for females with well-defined cleavage work just the opposite way, guiding blows in to where they're most inconvenient to be hit, so that doesn't count. 

Should a bladed weapon penetrate the plate, it must already be extremely compromised, so either the wearer is already rather injured, or he will be so shortly afterwards. having a non-moving surface to serve as "anvil" for the strike, like the ground, will help potential penetration. A prone individual wearing plate armor is about as safe as a turtle on its back with severely restricted ability to roll back over.

EDIT(ish): seems even longbows have problems punching through the breastplate part of plate mail.