The odds are very much in favor of the players, and allow them to try out things. They have enough health/luck to avoid dying and, even if they fall to zero HP, you can always treat that as "being captured" if you don't want to end the game.
Also, as for clues, impossible things do not get a "roll", so when they want to try something that lead to a dead end, tell the story of their impossible attempt (you cannot shoot arrow to the owlbear and hit the mark, you cannot slash the hellhound without your blade going through them unharmed, etc.).