That is not exactly the answer we wanted.
"Obstacles" is not about how they look like, but how they are made in the game.
Any position has a passability (yes or no), and some tiles have a damage effect (damage floor flag), and often objects are placed as blockades by events.
So which technique do you use for your blocks/hazards on your maps, so that we know what you want to override.
Do you want to override the passability on some non-passable tiles?
Do you want to negate the damage effect while walking on damaging tiles?
Do you want to know how to remove an event you placed to block player movement?
EDIT: and please try to give better descriptions that consist of more than a few words, no one here is a mindreader and we don't know what you want to do in your game