I don't know how to play 도깨비나라, but know how to play 가위, 바위, 보. The rule of 가위, 바위, 보 is the same as rock-paper-scissors.
fist for 바위(rock)
make a v-sign or spread index finger and middle finger with other three fingers are intact for
spread all your fingers for 보(paper)
가위 vs 바위 ->바위 win
가위 vs 보-> 가위 win
보 vs 바위-> 보 win