Mryntu

Similar to this question, I am curious about the effects of adding silver to your armor. Though adamantine armor (being the other enhancement able to be added to weapons/armor) has a specified effect (under magical item), I have found no entry as to what effects adding silver to your armor would give.

To add a bit more details, XGE says that adamantine weapons render each successful hit into a critical one. Likewise, Adamantine armor renders critical hits into normal ones. So I have it stuck in my head that since silver makes the weapon act as a magical weapon, then wouldn't silver armor give resistance to magical attacks? (such as elemental attacks)?

Is there any effects added to armor that has been silvered?

Its gauntlets could be used as silvered weapons.

However, there's no special effect official listed in D&D 5th edition for silvered armor.

However, certain armor types, such as scale mail, come with gauntlets, which could be used to make a silvered unarmed attack against creatures who are vulnerable to silver weapons. This is usually an inferior option to a dedicated silvered weapon. Likewise, you can use a headbutt as an unarmed strike, in which case a silvered helmet may be useful.

According to DMG p.142, items crafted by the fey glow in the moonlight, shedding dim light in a 5 ft. radius. Such an item is also crafted from silver or mithral instead of iron or steel. This isn't true of silvered armor in general, but may be true of fey-crafted silvered armor which you find.

It may also have ornamental value, if it is inlaid with silver filigree (again, DMG p.142). This may give it cultural significance, if it was created in honor of some event. This may gain you some respect in certain circles.

Silver plating may make it more valuable. Consider that as per DMG p. 135, a silver plated steel longsword with jet set in its hilt is worth 750 gp as an art object, so a similarly fine suit of armor may be worth considerably more than a normal suit.

I believe you are somewhat mistaken about Silvered Weapons:

Some monsters that have immunity or resistance to nonmagical weapons are susceptible to silver weapons, so cautious adventurers invest extra coin to plate their weapons with silver. You can silver a single weapon or ten pieces of ammunition for 100 gp. This cost represents not only the price of the silver, but the time and expertise needed to add silver to the weapon without making it less effective.

Werewolves and fiends are resistant to non-magical weapon attacks that aren’t silvered. There may be more creatures that are weak to silver but those are two examples. Silver-coated weapons are not considered magical; it’s just that the creature they are hitting is weak against them.

However, you might be able to do this using the barbarian's Path of the Battlerager (SCAG, p. 121), though it's normally restricted in the Forgotten Realms only to dwarves.

Battleragers gain the ability to use spiked armor, described in a sidebar on the same page, as a weapon. The 3rd-level Battlerager Armor feature lets them use a bonus action while raging to attack with their spikes, and automatically do damage when grappling creatures.

And at 14th level, Battleragers get the Spiked Retribution feature:

Starting at 14th level, when a creature within 5 feet of you hits you with a melee attack, the attacker takes 3 piercing damage if you are raging, aren’t incapacitated, and are wearing spiked armor.

So if your DM allowed you to either plate your spikes or make them entirely out of silver, you could in fact hurt a Werewolf or Fiend with your armor. I would imagine the cost to coat or make the spikes silver would be very high.

So if you happen to be a Dwarf Barbarian Battlerager in a campaign that is heavy in Werewolves or Fiends, and you have a lot of gold, it would be in your best interest to plate your spikes with silver. Actually, it sounds like a lot of fun.