List of Tricks


Hey. I figured it’s best to get a list of all of the tricks and all the intricacies of them we know up here to be freshly updated all the time. I’m taking a fair bit from the HL2DQ Tricks Text, because the tricks are established. I’ll change what’s required when it’s different for EP1.

Speed Swimming

Description: Using the sprinting ability to travel faster in and under water. If you hold the sprint button before you enter the water, you are able to keep your sprint even while underwater, until your suit power runs out.

Speed Crawling

Description: Using the sprinting ability to travel faster while crawling. If you hold the sprint button before you enter a crawl, you are able to crawl at faster speeds until your suit power runs out.

Bunny Hopping

Description: Jumping continuously at accelerating speeds. Jump while moving forwards, then jump again as soon as you hit the ground. If your timing is right, you’ll gain speed. Continue doing this upon each successive jump.

Crawl Jumping

Description: Jumping continuously while ducking to slowly decrease speed or speed through very small corridors. Identical to bunnyhopping, but while holding the duck key. This does not keep, let alone gain, your previous speed as bunnyhopping does, and in fact it deplenishes your speed fairly slowly. However, it can take you through tight corridors like vents much faster than you ever could speed crawling, provided you have the speed to begin with, and there are no turns.

Circle Jumping

Description: Jumping further than normal from a standstill.The idea behind this is to increase your forward velocity both by sprinting and by using extra speed provided by strafing. Turn left or right from the direction you want to jump towards, and then hold in the strafe key that will now take you in the direction you originally wanted to go. At the same time, hold in the sprint and forward keys. After about a fraction of a second, quickly turn back toward the intended direction and jump.

Collision Boosting

Description: Using speed and the slope of objects/terrain to propel yourself over and past obstacles. Simply charge full speed into an object or terrain. With enough speed, you can use just about anything solid to collision boost off of. However, the best objects are slanted much like a ramp. The height and distance you get from it depends on the slope of the object.

Dale Jumping

Description: Transportable collision boosting. Carrying an object while bhopping, preferably something sloped like a barrel sideways, then dropping or throwing it at your feet at just the right time so you collide into the top edge of the object and achieve a collision boost.

Gravity Jumping

Description: Using the gravity gun to boost yourself vertically or horizontally. The simplest way to perform this trick is to stand on object, preferably flat, crouch, look down, and shoot the gravity gun’s primary fire at the object. The object will rebound off the ground and throw you into the air. The height it gives you depends on the weight, area, your location on the object, and other such properties of the object. This can be done without crouching, and sometimes it helps to jump just as the object is rebounding off the ground for extra height, although this may end up stifling your jump instead. UPDATE: This is different for EP1, as some objects are far worse for Gravity Jumping. Also, the secondary ‘grab’ function I find much more useful and it sends you a bit higher than in HL2, which is quite useful on certain maps.

Advanced Gravity Jumping

Description: Gravity jumping with the additional aid of more complex physics manipulation. Same concept as gravity jumping, but simply more complex in it’s use of physics to gain height. For example, some objects can be tilted off their axis by duckjumping on top of the edge of them, after which they quickly return to their initial state. You can use the added force of the object’s edge trying to push itself up, on top of the rebounding effect from the gravjump, to propel yourself to even higher heights.Other examples, such as gaining massive height from a gravjump off the airboat, involve standing on the edge of a bulky object, then firing the gravity gun at it sideways, so that the object is thrown perpendicular to the ground, simultaneously throwing the edge with you on it upwards violently.

Ladder Jumping

Description: Climbing ladders at extremely fast speeds. For reasons not altogether understood by myself, if repeatedly jump and crouch while on a ladder, it sends you hurtling up it. That’s about it for this one.


Description: Using HL2’s physics against itself to repeatedly jump off objects and simulate flight. This is extremely different and far less useful than HL2 flying. HL2 flying required you to merely grab and then continuously jump on an object, which could then very easily be manipulated to fly around on. In EP1, this has been removed mostly. However, if you continously jump on AND grab an object, you can crudely imitate this. It’s pretty much only useful when against a wall, as that’s the most stable, and with bigger objects such as barrels or crates. However, if you have some speed going, you can leave the wall and begin to fly normally. This won’t last that long, but it can be useful in some maps. An example of doing this is this video. This is my run of ep1_c17_01, and you see at around 1:15 that I, though still against the wall slightly, am flying relatively freely.Again, this is difficult and far less useful or consistent than HL2, but it will be very useful for skipping parts of the game.

EDIT: Also, flying can be used without walls for certain bigger objects such as barrels or the square crates. Just climb on top of them, jump and continuously jump and press use. Again, very inconsistent and difficult, but good for quickly getting to a medium height.

Object Acceleration

Description: Using the same method as flying to accelerate horizontally. While flying, jumping occurs much more frequently as the “ground” you are standing on is constantly being pulled up to the same level as your feet. Consequently, you can fly while moving forward (from a standstill) to build up speed with bunnyhops faster, then duck and pull the object out from under you to resume bunnyhopping normally. This is only good for gaining speed for the first few seconds, before bunnyhopping normally would have been faster. I’m unsure about this one. It’s not as effective as in HL2, but it can be used I believe. Remember to use the new flying method.

Orb Jumping

Description: Using the force of a collision between an object and an energy orb to dramatically increase player velocity. Although orbjumping has been known throught the HL2DM community for some time, this specific single-player rendition of a jump using energy orbs was first performed by suga, as inspired by a video called “Josh2High”. The method involves first standing on a part of an object, where ideally the part of the object has small surface area but the object itself is large and heavy. Grab an energy orb with the gravity gun, and fire it at the object in such a way that the part of the object you are standing on is launched in the intended direction.Alternatively, as demonstrated by Chib, you are also able to boost off of an enemy elite’s energy orb, if you collide with it at the right angle.

Brute Acceleration

Description: Using the complicated properties of in-game models to launch yourself at tremendous horizontal speeds from a standstill. This works best with a small object with a complicated model, such as a piece of a broken bottle. If you duckjump on top of the object and stay there for half a second, then try to jump, you may find you are stuck either under or in one of the jagged edges of the object. However, you are able to move fractions of an inch in your intended direction. Using this technique, you can jump fast and repeatedly with virtually no time taken to land back on the ground. What this results in is the added velocity of many bunnyhops in a very short amount of time.Once you “jump” far enough away from the object that you are “released”, release the duck button and resume bunnyhopping with the additional velocity. As a side note, sometimes you may be “crushed” doing this trick, either because you clipped the object or a part of you was trapped between the object and the ground. EP1: I’m unsure if this works, but I’m putting it in just so people can experiment.

Stuck Jumping

Description: Using the game’s clip prevention techniques against itself to transfer large amounts of force to the player. In the unlikely event that a solid object passes through another solid object in the world, the game automatically tries to push the objects out of each other with tremendous force. The object continues to push until it is freed from it’s faulty position. This is why you are sometimes “crushed” when accidentally clipping inside of objects while doing seemingly innocent things in the game.To take advantage of this, it is possible to use forced animations, such as the closing of a door, the raising of a ramp, etc. to trap objects inside of the animated object, and deform both the physics of both objects. If the animated object isn’t necessarily an object, such as a door, then only the regular object’s physics will be deformed. When an object’s physics are “deformed”, it is holding large amounts of energy trying to push itself out, which can be transferred to the player when you touch it. For optimal height versus distance, it is best to duckjump into the diagonal of the object. Forces depend on both the size and shape of the object you are touching, as well as the way you touch it.

Enter Clipping

Description: Using the “entering” animation most common with vehicles to skip triggers and pass through walls. When you enter something, a vehicle for example, the player model is not actually passing through the area between yourself and the vehicle, but disappears, and is replaced by the model of the vehicle for the time you are using it. When it shows you entering the vehicle, it is only an animation, nothing more. For this reason it is possible to pass through triggers upon entering a vehicle, provided the width of the trigger is smaller than the maximum possible width between the player and the vehicle upon a successful “entering”. Using the exit animation, it is similarly possible to pass through walls, but this one is trickier. There are small areas surrounding the vehicle which are designated to be spots where the player is able to be exited, and are checked to make sure these places are clear before a player exits. If one of these places is blocked, it will force the player to exit into one of the other possible exit locations. If ALL the exits are blocked, it will not allow the player to exit until they are free. To trick the game into thinking an exit is free when it is not, it is possible to violently change the position of the airboat, usually via midair crash, upon exiting the vehicle near a wall. This is actually how I first accidentally discovered the glitch.There are other, simpler ways to exit through a wall, but these are dependent on the area. For example, in some places the vehicle naturally thinks an exit is free, but it is only by strange design of that specific terrain, and you end up being partway inside of a wall, after which you are automatically and instantaneously pushed to the other side. EP1: Unsure if this works in EP1, but I’ll leave it in again for experimentation.


Description: Blinking an NPC straight to it’s destination while it is in path mode.There are essentially three modes for an NPC to be in. We’ll call them Stand Mode, Follow Mode, and Path Mode. The latter is the one we’re interested in. This is the mode where an NPC is headed for a specific point on the map, and will continue to try to get there no matter what block it’s path. For example, even if you completely block an NPC’s path while it is in path mode, it may try to strafe around the objects for a few seconds, but it will eventually teleport on the other side or straight to it’s intended point, depending on how long it was delayed.Taking advantage of this knowledge, it has been found that holding or lowering an object over a “sweet” spot just above and in front of the NPC’s head while they are in path mode, most easily when they have just begun moving, will trick the NPC into thinking there is no way around the object and instantly teleports the NPC to it’s destination.

Orb Flying

Description: Walking on top of an orb held by the gravity gun

EP1: Not sure if it’s possible in HL2, but this was found by our own Typical :D. If you grab an orb (It has to be one of the free-floating ones, not one from a beam, though I believe ones that a broken beam that spits them out are good ones to use), then jump and crouch and look down, putting the orb underneath you, you can fly on it in a way. I’m unsure of the particulars of how it works. Jumping is a factor, pressing crouch is a factor, REPEATEDLY pressing crouch is a factor (I believe this causes a gain in height). There is a use of the directional keys, but again I’m not entirely sure.Demo of Orb Flying

Fast Rocketing

Description: Picking up rocket ammo at the right time to fire the rocket launcher much faster than intended

EP1: Discovered by suga a while ago, I only just noticed it in one of the old threads. If you are out of rocket ammo and hold down fire, you will hear clicks. If you keep this held down and then walk over some ammo, you will instantly fire it. Now, the next rocket can be fired as soon as the first rocket hits, so you have to time it right of you walking over the ammo to fire at the maximum rate. It takes a while to get used to, but it’s very useful. Thanks suga :smiley:

Purple Bug

Description: Abusing the game’s alt-tab mechanism to cause missing textures to appear on most surfacesEP1: Discovered by Typical, very helpful for the entirely dark levels. Load a demo then stop it. Alt+Tab Go back in to Half Life Load another demo. At this point you should have some purple textures. Then load your save, and everything is purple. You must be in fullscreen for this to work.

Reload Cancelling

Description: Changing weapons twice to cancel out long reload times. This is only really useful for the rocket launcher. It’s about 0.5 of a second faster than waiting for it to reload but it adds up.

So I hope that’s pretty much every trick that we yet know of for Episode 1. If I’ve missed out any, tell me. If any are wrong, tell me. Anything to do with it, tell me really :stuck_out_tongue:

#2 the end of the game you can teleport barney closer to the door so that he gives you the citizens quicker. Saves around a second.


Excellent. I’d say that saves a few seconds, rather than just one, but still great. I was trying to create a map that had an npc that constantly walked from one side of the room to the other and I practiced teleporting but I never managed it. Perhaps I had a bad item, or just my way of making the map was wrong.Cheers for proving that anyway.


Also flying is possible on certain objects which when used are close to your feet. Like barrels. =D


Ah, good to know. Looks quite selective about what you can do it with, but definitely good to know you can start it without the wall. You seem to be able to do it with the cube crates also, which is better as you don’t have to flip them for it to work, however they are breakable. Still though, good to know


Update with Orb Flying, thanks to Typical for that :smiley:


Updated with Fast Rocketing, thanks Suga :smiley:


Update with purple bug!


And ABH and AFH. Btw who wants to help me make some youtube vids for this shit.


Dude. List of tricks in the Episode One forum… and you want ABH and AFH?


Oops, stupid me.


Added purple bug. I get the feeling description isn’t right. Anyone got some good instructions?


Purple bugLoad a demo then stop it.Alt+Tab(Must be in full screen)Go back in to Half LifeLoad another demo.Load a save.You will know if it works when you load the demo as there will be some purple in places. To get back to normal:1.Alt+Tab2.Change the map.3.Load another demo.