It makes no difference if you read the walkthrough or not. Nowhere does it tell you how to cheat (and of course you won't reveal how, to do so here for obvious reasons) at "Rock, Paper, Scissors." So to answer your query, Yes I did read the walkthrough thoroughly.
Well, to be fair in the walkthrough we say how to cheat; here it is: you have to talk to the troll, and tell him you'd like to be his friend; then, you'll have to give him your snack. After that, talk again to him, asking him to play, but changing the rules this time. :)
Trying to obtain the saw when it's impossible, to win against Rock, Paper, Scissors with Shopenauer the Troll, very quickly makes this game too tedious to bother playing in my humble opinion.
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Well, to be fair in the walkthrough we say how to cheat; here it is: you have to talk to the troll, and tell him you'd like to be his friend; then, you'll have to give him your snack. After that, talk again to him, asking him to play, but changing the rules this time. :)