Forced: After a character commits to the quest, deal 1 damage to that character if it has not been dealt damage by another copy of Brambles and Thorns this round.
..and on both shores there were steep slopes buried in deep brakes of thorn and sloe, tangled with brambles and creepers. –The Fellowship of the Ring
While Sarn Gebir Rapids is the active location, the "when revealed" effects of Hazard cards cannot be canceled.
"What a horrible place! Just let me get out of this boat, and I'll never wet my toes in a puddle again, let alone a river!"
–Sam Gamgee, The Fellowship of the Ring