I don’t know the “right” answer, but I set it so if you hit something, it plays out some checks similar to as you described:

• If we collide with something but its only waist high, then we will have the player stop the grapple and attempt to vault over whatever it is.

• If we collide with something and its more than waist high, then we wait for a very small delay and see if we made any progress towards our destination. If not, end the grapple because something is in the way.

• Ignore all collision damage otherwise when grappling. Either we get stopped on the way and give up, or make it and then end the grapple.

… And last but most horrible of all:

• Do a completely different set of checks if the player is underwater when the collision happens.

All my games are janky though so I don’t think this is some ideal setup.

Edit: Cleaned up the collision damage part as I thought I handled it differently.

Oof, this reminds me of a personal experience.

Me: Oh this grapple system is easy, we’ll just push the player’s vector towards the destination vector.

Game: Oh but there’s a small object in the way that cannot be moved. This will make an immense amount of collision data per tick.

Me: Can’t we just ignore-

Game:

Well its seems like its lacking around here. We’re going to be the change we want to see and are forming a local Tulsa Filmmakers group.