Post/Author/DateTime	Post
#1 ProphetSword Oct 31, 2014 4:52:48	In my game last night, a Wizard in the party cast Invisibility on the party Rogue.  He then cast Blink on himself and began bouncing in and out of the ethereal plane.  This got me wondering if there are any rules about concentration and the caster leaving the plane.  I understand that he can still concentrate (as bouncing between planes won't be that distracting), but does that concentration do him any good if he is not on the same plane as the person that the spell is attached to?   Looking for solid rules as well as hearing how other DMs might have houseruled it.   Since I couldn't find anything, my houserule was that the caster had to make a standard DC 10 CON save to maintain it while passing through the planes.  Please let me know if there are any real rules I should be following instead.
#2 Timborama Oct 31, 2014 5:25:01	RAW there are no such rules (but many spells are limited by planar travel and are called out by this). I'd be less okay for something like Baator or Celestia, and pocket planes would be iffy. But a parrallel plane like Shadowfel or the Ethereal realm? Meh that's fine. I'd probably even consider the Astral Sea close enough in connection to the Material Plane   It's a fine houserule, but remember that the ethereal plane isn't that big a jump! And make sure your players know that you'll be doing this permanently, lest you pull a "gotcha" (albeit an accidentally improvved one) on your players when they do anything creative-ish (or, in your above case, just use 2 spells...)
#3 ProphetSword Oct 31, 2014 5:28:13	The player said it was fair to do that.  There was a discussion at the table.  We couldn't find any specific rulings, and I didn't want to bog the game down, so rather than end his spell unfairly, we made it a saving throw.  I told him I would research it later, which is why I'm asking about it.  I have no problems going back to the next session and letting them know that the spell won't break if he casts Blink (and to be fair, it didn't break it at the game either since he made the CON save the one time he had to make it, since the Rogue broke the invisibility immediately afterwards).
#4 Theros Oct 31, 2014 9:44:16	The description on page 203 of the PHB has that concentration can only be broken by the following. Casting another spell that requires concentration. Taking damage. Bring incapacitated or killed.   Normal activity such as moving and attacking doesn’t interfere with concentration.   There’s a stipulation that environmental phenomena can warrant a DC 10 Constitution saving throw to maintain concentration. But it implies the environmental condition is for the caster not the recipient.   It seems to me that the rogue is fine in this situation, but if it was the Wizard that was moving back and forth to the ethereal plane I’d make him roll the Con save.
(Reply to #2) paulstrait	Timborama wrote:
#6 Psikerlord Nov 01, 2014 1:10:39	Yeah I think that's a fair call, crossing the planar boundary might jolt your concentration.
#7 ProphetSword Nov 01, 2014 6:54:25	I have since reversed my ruling, anyway.  We're playing in Forgotten Realms, and apparently magic works fine on the Ethereal plane.  So,  I ruled that nearby planes where magic works is fine, but the outside planes would automatically break the concentration unless the target of the spell was with the caster when they crossed over.  That seemed fair to everyone.   We're actually playing in the 3.0 Forgotten Realms timeline.  What I find interesting is that 5th Edition makes references to the Ethereal plane, but it was destroyed in the spellplague in 4th edition.  Weird.
#8 Uchawi Nov 01, 2014 7:08:12	Technically the caster is in both planes (juxtapositioned) when blinking, otherwise how could they see where they are going. So I would not require a concentration check unless something disrupts the caster in the ethereal via an attack or similar method, or if the caster moves to a location and the terrain disrupts them. Each spell is a separate sub-system, so it would state a concentration check is required if one was necessary. But as the DM you are free to state if the environment or creature (ethereal or primar material) creates a situation that requires a concentration check.
#9 paulstrait Nov 02, 2014 12:21:58	ProphetSword wrote: