Reading the linked rules of adventure gaming, it is true that you can have arbitrarily hard puzzles without breaking any of them.
[spoiler for a two puzzles in Monkey Island 2 below]
The example for me is in MI2; there comes a point at which you are suspended over a boiling cauldron with a candle that is burning through the rope holding you up. If you are really clever, you will remember that earlier you got a drink that would thicken your spit (and you can't have not picked it up, since you needed it to solve a puzzle to get to this point). However, you can't spit at the candle, but you can spit at a shield on the wall, causing a ricochet to extinguish the candle.
I was stuck on this for months, finally got bored and played through the game again. The moment I got to the first time you need to spit I just slapped my self in the head.
[spoiler for a two puzzles in Monkey Island 2 below]
The example for me is in MI2; there comes a point at which you are suspended over a boiling cauldron with a candle that is burning through the rope holding you up. If you are really clever, you will remember that earlier you got a drink that would thicken your spit (and you can't have not picked it up, since you needed it to solve a puzzle to get to this point). However, you can't spit at the candle, but you can spit at a shield on the wall, causing a ricochet to extinguish the candle.
I was stuck on this for months, finally got bored and played through the game again. The moment I got to the first time you need to spit I just slapped my self in the head.