[ddoolin]

By fire do you mean weapon fire? Sorry, maybe it's obvious but my brain keeps jumping to literal fire.

[tedmcory77]

Yea, either direct (person with a rifle) or indirect (artillery/mortars). Ultimately obstacles slow, not prevent.

[tedmcory77]

This wiki article provides good clarity, especially the "obstacle negotiation" part.

https://en.wikipedia.org/wiki/Obstacles_to_troop_movement

[HonestOp001]

Correct, weapon’s fire.