How did he do it?

[ZEUS]

Hello. I came across a YouTube video to the record of 13:45 at the end of Prince of Persia. There were some strange things prince entered into a wall and reached the other side .. I tried to do it, but without success. Can someone explain to me how to do it?

http://www.youtube.com/watch?v=zYF3OMJeWms 3:38-3:42 (level 4) - The guard opened the gate .. I could not get it open.
http://www.youtube.com/watch?v=zYF3OMJeWms - 6:13-6:18 (level 7) - Into the wall and move to the other side
http://www.youtube.com/watch?v=FJRmrFzwxPM - 2:24-2:28 (level 10) - Jump in the hole and somehow comes up


I tried to do what he did, but I could not. Thanks in advance.

*I'm playing version 1.0
*I try to jump at the same timing and same place as a video to, but I still can not.

[Norbert]

Hi ZEUS, welcome to the forum.

http://www.youtube.com/watch?v=zYF3OMJeWms 3:38-3:42 (level 4) - The guard opened the gate .. I could not get it open.

See here and here.
"Stand next to the gate. Bump into it. Turn left. Turn right, press right again, and immediately press left."

http://www.youtube.com/watch?v=zYF3OMJeWms - 6:13-6:18 (level 7) - Into the wall and move to the other side
http://www.youtube.com/watch?v=FJRmrFzwxPM - 2:24-2:28 (level 10) - Jump in the hole and somehow comes up

See here and here.
Both are the result of the so-called "overflow bug". An explanation by David can be found here.

You may want to check out this entire thread and this page.

[ZEUS]

Hi ZEUS, welcome to the forum.

http://www.youtube.com/watch?v=zYF3OMJeWms 3:38-3:42 (level 4) - The guard opened the gate .. I could not get it open.

See here and here.
"Stand next to the gate. Bump into it. Turn left. Turn right, press right again, and immediately press left."

http://www.youtube.com/watch?v=zYF3OMJeWms - 6:13-6:18 (level 7) - Into the wall and move to the other side
http://www.youtube.com/watch?v=FJRmrFzwxPM - 2:24-2:28 (level 10) - Jump in the hole and somehow comes up

See here and here.
Both are the result of the so-called "overflow bug". An explanation by David can be found here.

You may want to check out this entire thread and this page.

Thank you very much! I succeed to trick level 4 (3:38-3:42)

But unfortunately I could not make the two other bugs in level 7 and level 10. It just does not work.
Bug of level 12 actually succeeded (http://www.youtube.com/watch?v=FJRmrFzwxPM - 5:16-5:21), but at level 7 and at level 10 I can not..and I tried to make the same timing of a video from YouTube.

*Sorry for my English

[Norbert]

[...], but at level 7 and at level 10 I can not..and I tried to make the same timing of a video from YouTube.

Well, it may not be super-easy to time it right, so you may need to give it several tries.
To practice, you could use a level editor to place the prince at/near the location(s) in question, and then restart the level with Ctrl+a after each failed try.
(The one in level 7 isn't difficult. In level 10, if you can't get it to work, try hanging on the ledge where the loose tile was before making the jump.)

[ZEUS]

[...], but at level 7 and at level 10 I can not..and I tried to make the same timing of a video from YouTube.

Well, it may not be super-easy to time it right, so you may need to give it several tries.
To practice, you could use a level editor to place the prince at/near the location(s) in question, and then restart the level with Ctrl+a after each failed try.
(The one in level 7 isn't difficult. In level 10, if you can't get it to work, try hanging on the ledge where the loose tile was before making the jump.)

Thanks for the answer. Eventually I succeed the two bugs.

I have one last question about this trick: http://www.popot.org/documentation.php?doc=Tricks#22

Did this trick is a matter of timing, or there's something else? Listed you can do this trick at level 1, like here: http://www.youtube.com/watch?v=zYF3OMJeWms - 0:17 to 0:20

He performed this trick without a sword. I tried to do it, but I can not. The guard always succeeds to kill me. Do you have a idea how do I make this trick without the guard will hurt me?

[Norbert]

Did this trick is a matter of timing, or there's something else?

I don't know the details, but it's not just timing. When you jump into the guard, the distance between you and him matters, and most likely also the horizontal position of both in the room. This is because the prince (the game) behaves differently depending on the location he's at. For instance, in the trick video I've just added here, if the loose tile that doesn't fall down - the one the prince doesn't even touch! - is not there, that trick won't work, because the prince simply doesn't jump. Another example: if you press down briefly, the prince normally moves forward exactly 7 pixels, but near the end of tiles it's 6 pixels. To survive, you have to make sure the guard tries to hit you before you jump into him. You could try to ask Ma5terViking (hiking_viking at jippii.fi), the guy from the video you linked to, for more information. It seems he's using it a lot in his speedrun... maybe he has some advice/suggestions for you. Also, there are a lot of good players on this forum (like Bap, yaqxsw and Moscow Tracer), maybe they know more. MP forces the player to do it several times in level 1 of his mod "Persian Nightmares", most people will probably use cheats and press "k" to kill those guards.

[David]

Another example: if you press down briefly, the prince normally moves forward exactly 7 pixels, but near the end of tiles it's 6 pixels.

I guess this is a rounding error that happens because the X coordinate of the kid uses a coordinate system different from the screen coordinates.
This is described in the PDF at http://www.popot.org/documentation.php?doc=OldDocuments, on page 2 and there is a drawing about it on page 7.
3 logical pixels will map to 3*(320/140)=6.85 screen pixels, which is just a bit fewer than 7.