Fougasse?

[Worrier]

Is there any way to unlock the fougasse?

If so how do you use it?

Thank you

[LSD]

Only light infantry can deploy them, and they're only available during "dug in" deployment, i.e., when your army has been stationary for 2 or more turns.
Normal light infantry (excluding rangers and native light infantry) can deploy a fougasse during this time.
Elite light infantry, such as the Green Jackets, Ferguson Riflemen and the early game Fraser's Rangers can deploy the "advanced" fougasse, which is much more explosive.
They detonate when enemy soldiers cross the red "beam"-like thing infront of them.

[Worrier]

Ohh right, thanks, but can my light infantry use it straight away or do I need a certain technology?

[DenmarkRules]

They can use it straight away under the conditions LSD mentioned.