Concentration and line of sight/effect

[Bellberith]

do you have to make concentration checks when the spell you are concentrating on leaves your line of sight/effect?

[Daishain]

Not by default, but it is left up to your DM to determine what events could threaten your focus. If he thinks not being able to actively see the subject is a problem, then he is justified in making you roll a concentration check.

Do note however, that all of the listed examples that would force you to make such checks are events that directly disturb you. Getting wounded, being on a rocking boat, etc. So the DM does not have a particularly firm precedent.

[odigity]

do you have to make concentration checks when the spell you are concentrating on leaves your line of sight/effect?

I hope not. That would interfere with my fantasy of casting Hunger of Hadar at party full of nobles then running out and barring the door behind me.