OoB Save/Load Movement in Half-Life



Originally found by WindedCone on the PS2 version of Half-Life, with YaLTeR then discovering that it works on Blue Shift’s WON version (which carried over some stuff from the originally intended Dreamcast version, hence the testing). I decided to go ahead and test it out on Half-Life and discovered that it works there too.

This trick only works on very early versions of the game. The latest one I could get up and running that has this trick was, released in 1999. It’s commonly used in Source speedruns and this particular movement is most similar to Half-Life 2’s ‘Old Engine’, moving you upwards after you crouch, save and then load.

The only methods of getting OoB (out of bounds) that we know of right now are via “leaks” in the map, or through triggerdelaying and then getting stuck in a wall. I tried getting stuck with snarks and tripmines and couldn’t replicate the clipping.

We haven’t found a confirmed use for this yet, but I’m hoping by sharing this video others will be able to look into possible routes.

EDIT: Confirmed working in Half-Life and Blue Shift, however doesn’t seem to be mod-compatible, so we would need to find a later version to find out if it works in Opposing Force. Unfortunately the version I’ve been using currently is the only one I could get working that has this trick. I can confirm it doesn’t work in Gunman Chronicles (which makes sense since it was released in 2000).


Really interesting, hopefully you can do some cool stuff with this!


This is really interesting, but you’d have to find a good few skips with it for it to be useful in a full run since the FPS is capped. Having said that, I never stopped to consider how much slower capped FPS actually is… infinite health door would obviously be 10 times slower, but for movement in general there are plenty of ways of getting up to speed like object boosting and stuff. So yeah, excited to see if any skips are found utilising this! And good job figuring this all out of course.


If you can find a way of clipping into one of the walls that are vertically aligned with the ‘fire’ button in Blast Pit, you could pretty much skip the whole of that chapter.

Also, I managed to clip into a wall in Questionable Ethics near Barney, but after moving upwards for a bit it turned out there was a ledge in the way that made me go back inbounds. If you could find a way of getting on top of the map there and then getting into the exit area (with the rotating door) you could pretty much skip the whole of that chapter also.

The FPS cap is 72 in this version as opposed to the later WON versions which are capped to 100. The exact difference between values can be seen in this sheet that Arianon made a while back.

Even if the timesaves are only small I think it’d be cool to see some TASes of the routes just for entertainment.


Well if the timesaves are small they’re still there. :stuck_out_tongue: And the purpose of TASes is entertainment so I’m with you on that one.


So, does getting stuck and boosting yourself with an smgnade/gauss make you change the direction you clip in?


Nope, then it would most likely be alot more useful.