Stroop is a game you play under the pressure of time whilst being asked to think laterally.
The game consists of a deck of cards with words on – different colours, different length of letters, solid or hollow, big or small (upper/lower font). Each word describes several of the other cards – so the words are things like yellow, solid, hollow, blue, small, big, four, six and so on – the numbered cards referring to the number of letters in a given word.
In each round players are trying to get rid of their cards by placing them on top of an ever-growing discard deck, as the first player out wins the round, and will have less cards to get rid of in round two. But the brain-melting comes in here – in round one, you have to add a card that the top card on the discard deck describes. In round two, you have to add a card that describes the top card instead!
So you’ve just gotten your head around the logic of the first round when suddenly that logic is flipped – and remember, the game is a race! First out in the final round wins the game.
I think this is the only game I’ve played where some players literally abandoned it halfway through – not out of disdain, but in sheer bamboozlement! It suits the quick-thinkers; the puzzlers and riddlers: those who can ignore the instant brain response of the word ‘Yellow’, for instance, and instead see that the word on the card is composed of six, small, solid letters. If those aspects describe the top card on the discard pile (or vice versa in round two) then you get it on there as quick as you can, before anyone beats you to it. If you’re too slow the card changes courtesy of someone else, and you’re back to square one! It’s like Dobble on steroids.
No direct sabotage, just the overall and overt pressure of it being a race.
None on the rules, plenty on the strooping: constantly being asked to ignore the word's meaning and look at its appearance can drive you to distraction.
You can't play it over and over in one sitting - that would be exhausting! - but for the right group the mental challenge here is the stimulus.