Weird mouse glitch with HL2OE


Hello, so I recently downloaded the HL2OE source mod to get some nostalgia. It’s pretty great, but the mouse seems to jump on it’s own, without me even touching it. Sometimes it’ll just do a 180 for no reason, or just spiral up, and even when it’s not doing that, it’s very stiff, and jumps and stutters a bit. it’s very annoying when shooting and your mouse just starts to move on its own. This is the only game that I know of that has this issue. I’ve also tried turning mouse smoothing on and off, unplugging my gamepad, etc. Nothing seems to fix it. Anyone know of a fix?

Apologies if this is the wrong place to post this.


I understand that the unpack comes with rinput, have you been using that?
If so, try without.
If not, maybe try with it?

Otherwise, I’m not sure


The Old Engine source mod doesn’t have rinput, and the source unpack didn’t seem to have the right version of half life for me, but I might have just screwed it up.


I do not know if this is true, but I believe the issue is auto-aim. Somehow the old engine’s autoaim is broken, so playing on a difficulty other than easy should fix this.