[@KatherinWinter] I can see the communication problem, obviously we want to be able to talk quickly but perhaps if there are a short list of signals. Noises travel best (no line of sight problems and people could repeat them) but you aren't going to be able to talk a lot during the heist, only to warn people to run or something.

Magic or modern are both good solutions but we might have people wanting to change characters with those things involved.

It will probably just have to be well planned out before hand, scoping everything out for a few nights before, watching guards and stuff.