Post/Author/DateTime	Post
#1 Hepius Feb 11, 2015 18:51:40	One of my players wants to use his bat familiar's echolocation ability to disprove illusions. The bat's eyes would see the illusion but the echolocation would show that there is nothing really there.   I'm concerned that this ability would be overpowered.
#2 cbwjm Feb 11, 2015 19:06:36	You could say that the illusions cover all the senses and so this wouldn't work. I think in the past there were different types of illusions and those that were figments were actually in the mind of the observer which would cause the bat to believe that the illusion was real, perhaps by creating false echos in its mind. I'm not sure if there is that distinction in 5e though.
#3 slumgum Feb 11, 2015 20:11:54	Be specific, which spells/abilities are creating the illusions?  If visial only then Blindsight should allow them to see through.
#4 Archon007 Feb 11, 2015 21:04:50	Hepius wrote:
(Reply to #4) Macv12	Archon007 wrote:
#6 Goober4473 Feb 12, 2015 8:17:17	slumgum wrote:
#7 Coredump00 Feb 12, 2015 11:27:26	Echolocation and 'auditory' are not the same.  An illusion of a girl screaming is auditory... but the girl would be obviously non-existent using echolocation, you would just hear a scream from nowhere.       I don't think it would be OP,  they have to suspect there is an illusion, then spend an action to look with the bats eyes....    I would not let him give the bat a command of "Whenever you see an illusion, let me know"... would not work.
#8 transcendantviewer Feb 12, 2015 16:13:42	In my opinion, this is a difficult question to answer. There's multiple solutions to the problem as well as multiple problems to solve. The one that most intrigued me out of the options mentioned by others was that the wizard could simply have his bat alert him to when it hears something, but doesn't find anything with its Echolocation. That's a viable option when facing visual and auditory illusions. Personally, if a player was smart enough to put that together to get around the illusion, I'd let them him have it. It would make for a great defense and give that player a sense of "I just did something awesome!" The DM should never bar a player from doing something unless it's actually unable to be done. Like here's an example: a party of adventurers are faced with a tall, massive maze. One comes up with the solution of "I say we cast Levitate and lift up to the top of the maze and just walk over it." That player may have just dismantled an encounter, but you shouldn't just tell them no because it took a half an hour of playtime and crinkled it up, reward them for thinking outside the norm. But, if there's absolutely no way that they can get above the maze, then they have to go through. Like the maze is underground and has a stone ceiling or the caster burned through all of his 2nd level spell slots and has no stronger ones.