All sound unless "friend" #2 is either foolish, or, trying to get you killed.

Just had a cool idea: let's say that one wins by getting the medal and loses by perishing or having someone else get the medal, and all players want to win. From palyer 2's perspective, if he says "I don't know" and he's wearing a red hat, then you will win by following this video's reasoning. Moreover, if he's wearing a blue hat, you will also win with similar reasoning. Thus, saying "I don't know" has a 100% chance of losing to you, and player 2 will never say that if he's a good logician. He should instead bite the bullet and guess "blue" with a 67% winning chance. In fact, player 1 should never say "I don't know" for the same reason in this scenario.

Animations were great, explanation was simple yet complete. I really enjoyed this. The only thing was the paper background animation was a little distracting. Other than that, I loved it!!

Your videos are extremely underrated. The only thing I would wish for would be harder puzzles but I guess they will come in later videos.

YOU DIDN'T TELL US THE FRIENDS WERE PERFECT LOGITIANS THAT DON'T TAKE RISKS

Here's how I came to the same conclusion.  As person 1, I can reason as follows:
1. Everyone knows that the only way they can know the color of their own hat with no further information is if they see two blue hats.
2. Person 2 passes. That's no surprise. With 2 red hats visible to me, I know person 2 must pass, since he cannot see 2 blue hats.
3. Person 3 passes, which means (a) he does not see 2 blue hats (but we already know that), and (b) he realizes that person 2 did not see 2 blue hats.
4. Now person 3 knows either his hat is red or my hat is red.  If my hat is blue, then person 3 would know that his hat must be red.  But he doesn't know that or he'd say so.
5. Therefore my hat cannot be blue.  It's red!

Instructions unclear
Guessed the wrong hat and got sent to the void
Great video bud ;)

Brilliant, I thought this was impossible to work out until you explained how, well done...!

Great video!! Very interesting and amazing animations!

1:48 I swear that number is everywhere

But friend #2 can assume in a perfect logician and lie to get me killed by my own sound deduction

I want more videos like this! Great work

Can you give one more example of this...also great video bro all the best for SOMEpi win🎉

Great vid!

I went through this thought process: If friend 1 says 'idk', then you can have either color, because either situation you cant be 100% sure (friend 1 sees blue and red, or red and red).  Now friend 2 takes that information, and if your hat is red, they see the same thing.  If they see blue, they also see red or blue BUT it tells them that if their own hat was blue, friend 1 would have known their hat is red because there are only 2 blue hats in the box.  But because they say 'idk', they MUST see two red hats.  Therefore your hat is red.  (basically combining both into one thought process lol)

Locking in the answer at 2:08:

#1 is uncertain because he does not see two blue hats. #2 is uncertain because he sees that #1 is uncertain and main character's hat is red. If main character's hat had been blue, then #2 would know that his hat would have to be red for #1 to be uncertain. So the answer would be that your hat is red.

Except that's the wrong answer. This is a prisoner's dilemma where everyone cooperating gives 3 points (a medal or something), everyone defecting gives 0 points, and cooperating when someone defects gives -99999999999 points (i.e. death).

I feel like strict 'proof by contradiction' is not strictly necessary here, when we can use Proof By Elimination more directly, each stage of the guessing process eliminating possibilities of what could have been seen by each person. It is a similar logic, but doesn't rely on the 'follow each assumption to its conclusion' methodology, as failure to find a contradiction does not mean one does not exist, it could just mean you didn't do the right steps to get there yet, which can make proof by contradiction more frustrating to use sometimes.

Friend 1 says he does not know. Since, if he saw two Blues, he would know his was red, this means he either sees two Reds, your Red and 2's Blue, or your blue and 2's red. Friend 2 now has this information.
Friend 2 says he does not know. Since he can see your hat, he is able to eliminate any possibilities remaining from what Friend 1 could have seen based on this new information. Seeing you have a blue hat would eliminate the two possibilities that have you in a red hat, leaving only one left and so he would know. That did not happen, so he must have seen you wearing a red hat. You now have this information.
Since both remaining options demand that your hat is Red, you know that your hat is red. Technically, you don't even need to look at either of your friends' hats to know this at this point; you need only be aware that your two friends can see both hats that are not theirs.

bro i just watched this puzzle from another youtuber

Person 1's unsureness ensures that they are not both blue-hats, person 2 knowing this, and seeing person 3's hat, knows what their hat color is, the opposite of that. so person 2 will know, if person 2 is unsure, that must mean: Person 2 has a red hat and person 3 is a blue hat

Make possible combinations, then evaluate rules that eliminate the combinations each.

Here’s a related (but mathematically unrelated) question. What are the odds for each player winning the game assuming they only answer with 100% certainty.
Additionally, if they can only make 1 guess, what strategy can each player use to maximise their own chances of winning?

If I play this game I will play as the third player because it has a 4/7 chance of winning

(Player 1, player 2, player3)

1. First possibility: (Red, Red, Red)
Winner: Third player (as in the video)

2. Second possibility: (Red, Red, Blue)
Winner: Second player (because in this possibility the first player will pass, then the second player will immediately know that he is red because the third player is blue and the first player must have won if he is also blue)

3. Third possibility: (Red, Blue, Red)
Winner: Third player (because the first player will definitely pass and the second player will also pass and the third player will definitely think if he is blue then the first player must have won, then he is red)

4. Fourth possibility: (Blue, Red, Red)
Winner: Third player (Similar to the third possibility because if the third player is blue then the second player must have won)

5. Fifth possibility: (Red, Blue, Blue)
Winner: First player (It is clear that the first player will win here)

6. Sixth possibility: (Blue, Red, Blue)
Winner: Second player (it is also clear that the second player will win here)

7. Seventh possibility: (Blue, Blue Red)
Winner: Third player

We can see that the probability of the first player winning is 1/7, the second player is 2/7, and the third player is 4/7

So the third player will be at an advantage in this game if the players want to win and have enough logic to think that way.