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Jul 8, 2012 | 6:59 AM EDT
  • Daily 2nd Place July 9, 2012

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UPDATE 4 (8th September 2012): IR/RATIONAL INVESTIGATOR ANNOUNCED! /sharedfiles/filedetails/

UPDATE 3: ir/rational has made the front page with 45,000 plays in under a week! Thank you everyone - and keep your eyes peeled for announcements in the coming months!

UPDATE 2: Walkthrough available here: /2012/07/irrational-walkt hrough.html

UPDATE 1: Made 10,000 views and the Popular Games list in 24 hours! Thanks to everyone who's played!

Argue the toss in a twisted tale of logic...

In ir/rational you complete, create and discredit arguments by selecting propositions and filling in the blanks. It's a puzzle game based on propositional logic, and a graphic adventure all in one - only here you don't so much need to escape the room as prove why you'd even want to.

- Unique, language-based argument system: formulate logical proofs to progress through the game

- Dark philosophical comedy by Tom Jubert, writer of Penumbra, Driver: San Francisco and FTL.

- 10 screens and roughly half an hour of intelligent, challenging and inventive gameplay

- Musical score by award-winning composer Mikko Tarmia

My website:
My narrative design blog, Plot is Gameplay's Bitch:

- Click to progress story
- Complete the arguments by selecting options from the drop-down menus

NB Some systems don't display all the dropdown options at once, and you have to use the arrow keys to scroll.

If you can't see the right answer, chances are you can resolve the problem with the arrow keys. Hope it's not dampened your enthusiasm!



Rated 4 / 5 stars

This game is very interesting and pretty dang tough. Very good game!


Rated 5 / 5 stars

The game is... just nothing but mind blowing. It makes you think in odd and complexing ways in order to figure out why the something has done or said so. In order to solve a problem, you must identify why the statement above is true and then fit and see how it is true. Above all, great game to make and truly mind boggling!


Rated 4.5 / 5 stars

amazing its hard to find philisophical puzzles in games and wspecially ones that make you think. HOWEVER it is short. also the machine is the prototype of GlaDos

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Rated 4 / 5 stars

A wonderful game! The ending, as others have said, was a bit of a let-down. 4 Stars.


Rated 4.5 / 5 stars

Dear Creators,

I registered here on NG because I think there is a flaw in the argument lines of LEVEL 9.


I figured out, that the yes/yes/yes/probably are the machines answers, however, the actual mistake is in the arguing itself:

1. If the machine has contradicted itself, then the machine is not perfect.
2. The Machine thinks smugness is a relevant clue.
3. The Machine thinks smugness is a red herring.

4. IF the Machine thinks smugness is a relevant clue AND The Machine thinks smugness is a red herring then ......

And this is the part where I got stuck, Something like this should follow: then the machine doesn't know what a red herring is.

INSTEAD you have to write "the machine has contradicted itself" which CANNOT be placed here since it is in line 5.

In other words if you deduct with the "then" in line 4 that the machine has contradicted itself, then line 5 is a redundant line!!! Redundant, because it echoes the deduction already made in line 4.

So you either change the "then" part in line 4.. OR remove line 5.

I don't know if I'm making sense here. You have a deduction in line 5, which has already been deducted at the end of line 4.

At least please consider my post. I would also appreciate if the creators addressed this issue. Thanks and great game!

tjubert responds:

Hi! It makes sense, but I'm afraid, as far as I can see, it's not broken int he way you think. It's percetly okay to repeat the same clause in a different context, as 'the machine has contradicted itself' is here. First it's part of an IF-THEN, then it's stated as a conclusion (since we knwo the IF part of the statement has been satisfied. It's a bit like having to show your working in maths.

What's actually a problem with one of the possible solutions to that puzzle is that you can use both smugnes is a red herring and smugness is a relevant clue together, and strictly speaking you should have a premise which states that they mean the same thing. Actually, that's a much better puzzle. Next version!