Does protection interfere with concentration?

[Zebulon Ecthelion]

My paladin keeps losing Shield of Faith for no apparent reason (I don't see him losing concentration checks), but Shadowheart doesn't seem to have the same problem. Is it protection screwing with my concentration? Or maybe something else?

[Yojo0o]

What do you mean by "protection" in this context?

[Amix]

I suppose you mean Tyr's protection/Shield of faith spell.
As per D&D rules a character can maintain only one type of concentration. The spells of concentration do not stack.
Maybe you are casting Shield of faith from Sword of justice and then Shadowheart is casting it on your Paladin. In that case Paladin will lose his/her shield of faith spell and Shadowheart's spell will override that.

[EricHVela]

It might not be a concentration thing.

In 5e, two spells that offer the same benefit will not stack unless the spell specifically says it does. (I think the PHB states that anything offering the same effect, item or spell, won't stack unless the description says so.) The spell with the stronger effect will win and the losing spell will either cease or have no effect.

(Don't try to stack a weaker spell on top of a better one, and don't cast a shorter duration of a stronger spell on top of a weaker one. The duration of the winning spell is how long the spell lasts. You can't extend a stronger spell with a weaker one that has a longer duration as you'll just waste the weaker spell altogether, and you can end a weaker spell prematurely with a stronger one of a shorter duration.)

[Recjawjind]

Originally posted by Yojo0o:

What do you mean by "protection" in this context?

Originally posted by Amix:

I suppose you mean Tyr's protection/Shield of faith spell.
As per D&D rules a character can maintain only one type of concentration. The spells of concentration do not stack.
Maybe you are casting Shield of faith from Sword of justice and then Shadowheart is casting it on your Paladin. In that case Paladin will lose his/her shield of faith spell and Shadowheart's spell will override that.

Pretty sure the are talking about the protection fighting style?

[Mosey]

The 'problem' is the paladin is almost certainly being hit more often, thus making more concentration checks than the squish cleric. Fail one of those, and your spell is gone.

EDIT:
It's also possible the paladin just has much worse CON, but since it's Shadowheart I really hope that's not the problem.

There's also a leather set of armor from the Goblin Camp that has advantage on concentration checks, but I'd assume the OP would notice in that case.