Chamber 18 : turret room skip strat


Hai everyone,

I’m new to SourceRuns and I use to perform Legacy No OoB speedruns (not sure about that, but I mean not using saveglitch/edgeglitch nor going OoB) of Portal. I’m a beginner, so I don’t know much things about speedrunning this game.

However, in chamber 18, most tutorials I’ve seen showed how to skip the turret room by placing a camera in front of the door, so that the door would stay a little bit open.

The thing is, I usually perform a strat that I discovered myself, which is not really hard to do, and I’m surprised that I’ve never seen such a trick anywhere else.

Here’s what I do :
(Well I did it really slow because my computer lags as hell while recording the screen.)

Did somebody already know about this trick ? Or is it a new discovery ?

(Please excuse my probably bad English.)


Hello, that’s an edge glitch and it’s pretty known. Also welcome to SourceRuns!


I think the current legacy route is about as fast? I’ve seen people do the edge glitch to clip through the door like you did but from a different spot so I think this is sort of new.

EDIT: Also to clarify, edge glitch is allowed in Legacy, but you cannot do any edge glitches that put your “body” out of bounds.


I thought the edge glitch was when we are stuck on the portal, but still able to shoot from the wrong position, while in my video I just actually pass trhough the portal. Is it still an edge glitch?

I was just wondering about that, and I thought that doing what I do (I mean, doing it really fast) may be faster, because it only requires to shoot one Portal and jump on its extreme edge. Not sure though…


“I usually perform a strat that I discovered myself”
I’ve been doing that for years.
Yes, it’s an edge glitch and it’s allowed in current Legacy No OoB rules.
Honestly, I prefer this strat than the common strat used in Legacy; but I didn’t discovered it, and I am sad to say you didn’t either.


It still seems different from what the website is saying about the edge glitch. The glitch I’m doing requires to place the portal so that it goes a bit over the edge of the wall. As you can maybe see in the video, there’s a small spot on the wall where I can’t shoot portals, and I placed my portal like one pixel under that spot. Shooting a portal higher would leave a blank space between the portal and the edge of the wall. Leaving no space makes me able to “go through” the portal.

The edge glitch described on this website seems to work even with a blank space between the portal and the edge, and requires the player to be stuck on the edge, and then shoot a portal like if the player position was at the other portal.

I’d be surprised if these two glitches are both being called “edge glitch”, because they seem pretty different…


Well, this edgeglitch and the one on the website are pretty much the same. Being teleported through the portal is what happens when there’s not enough space on the other side to stop you from doing so, for example, if the portal is too close to the edge of the wall, or if the wall that would be obstructing you is very thin. TheSunsetBear and Can’t even exploited that in their portal unity run by using edgeglitch to pop back inbounds. They’re the same glitch, but the circumstances change the glitches effects. Does that make sense?


Yeah I guess it might be somewhat confusing but people use the term edge glitch for both shooting a portal whilst being on top of one and popping out of a portal by walking into the top(or side) of the other portal.