Would moving through a silence or antimagic field stop a spell being cast?

[holywhippet]

If a character is casting a spell with a longer casting time than 1 action (eg. conjure elementals) and they happen to move through a silence spell area or an antimagic field, is the spell casting immeditely cancelled? Or would it only be if they are still standing in either when the spell finishes or when they end their turn?

[DragonBaneDM]

As a DM I’d shut it down, yeah. If the spell has a verbal component, then they’ve gotta be chanting and complete the whole shebang

Maybe I’d give a...I dunno, a Perception check to see if they spot it, but if they go in there, spell doesn’t fire, slot gone.

[holywhippet]

OK, thanks. I dont think the slot wouldn't be wasted though - the rule state you don't lose the slot in the case of having your concentration broken.