Rainsford fell off of the boat whilst trying to grab his pipe, falling into the water and being left behind by the boat.
General Zaroff had explained to Rainsford that he had grown tired of hunting the same things, and they were becoming easy to hunt. He says he made up a new animal to hunt- humans, causing Rainsford confusion.
Rainsford had agreed to playing the game with the general, seeing as he was basically told he couldn't escape or it'd be far worse than the hunt would be. He slept throughout the night so he could be alert for the game.
When the hunt began, Rainsford was allowed a head start and rushed into the woodeed area to hide from Zaroff.
Rainsford had tried three traps on the general. He tried a disquised hole in the ground, capturing and maybe killing Zaroff's best dog. Then he tried a stabbing trap, ending up stabbing the generals acquaintance. He then managed to kill Zaroff.
Rainsford won the so called 'Game' and was able to return to the castle like home General Zaroff once lived in. Rainsford slept peacefully that night in the bed.