Forest Flies from NM PtM says, Forced: after you engage this enemy, deal 1 dmg to each exhausted character. Considering I am playing Samwise, would his response trigger before the forced effect of the Flies? (Which also shares the "after you engage" text).

Forced effects trigger before player activated responses... sorry! Sam will have to take damage.

Thanks, thought so.

Yes forced is force. That why is call forced!