The shiftlock glitch that I’m talking about is the one where you use shift lock to get through walls that have corners shown in R6. I don’t want to go to R15 either.
I was thinking about if there’s any way to kick people, kill them, or teleport them back for shiftlock glitching. I mean I could set up raycasting but it’d probably be a very trippy system.
Is there any scriptable way to detect this? (not manually laid parts)
No there is no way to detect it.
What about putting a brick where a player is, and a second later, raycasting from the brick to the character’s head and seeing if there’s a part that has collisions on in between?
It’s not worth patching glitches like this it will probably falsely identify people doing the glitch most of the time. Most people don’t even use glitches, they mostly just use exploits. I think it would be better to focus on anti exploits.
You can disable the shiftlock if you’re interested. By setting the StarterPlayer.EnableMouseLockOption to false, you can do this manually without a script.
My method also detects noclipping, i guess. I could even add a thing where it tells staff and staff watch the player.
That might be a good idea but shift lock is a core feature of the game and without it, the game doesn’t have a certain level of “crispness” if you know what I mean.
You can put walls behind walls, so even if someone shiftlocks, he wouldn’t see much.
The issue isn’t about glitching, I just don’t want students glitching into the admin offices or other classrooms.
If I recall correctly, unions were able to cull the corner glitch. I recall unioning my door thresholds and that prevented users from corner glitching. In other cases I’ve just used invisible bricks over the door plus some in such a way that corner glitching couldn’t happen.
Unions are working fine for my case. Thank you very much 
You’d also have to disable first person if you want to go this route.