Advanced Movement Tech in Left 4 Dead 2

A quick explanation of advanced movement techniques possible in the game: Left 4 Dead 2.

TIMESTAMPS

00:00 Intro
00:18 Quick Ladder Climbs
02:16 Idle Warps
04:01 Stuck Warps
06:15 No Ledge Grabs
08:26 Fall Interrupts (Propane Tanks)
09:51 Fall Interrupts (Explosive Ammo)
10:23 Fall Interrupts (Alternative Strat)
11:15 No-fall-damage Buff Persists
11:58 Mounted Gun Boosts
13:32 Infected Boosts
15:18 Tank-punch Boosts
16:44 Strafe Jumping
19:13 Bunny Hopping
22:02 Crouch Jumping
22:37 Crouch Bunny Hopping
23:30 Outro

Useful commands:

sv_cheats 1
(Enables cheats. Needed to use most other commands.)

map [map name]
(Needed to load into maps. All start with c# for chapter number and then m# for map number. Example: c1m2 is Dead Center map 2: Streets.)

director_stop
(Disables random common and special infected from spawning. Use director_start to re-enable.)

sb_all_bot_game 1
(Makes it possible for everyone on the survivor team to be a bot.)

jointeam 0/1/2
(Used to join the spectator team, the infected team and the survivor team.)

sb_stop 1
(Disables survivor bot AI. Use 0 to re-enable.)

kick [survivor name]
(Kicks a bot from the game. Mainly used to stop your survivor from periodically annoyingly yelling “where is everybody.” Can be used to remove special infected too. Example kick tank.)

nb_blind 1
(Makes infected blind. Useful when you spawn then so they don't attack.)

z_spawn [infected name]
(Used to spawn special infected. Example z_spawn witch to spawn a witch.)

god 1
(Enables god mode. Use value 0 to disable.)

hidehud 4
(Disables the hud. Use number 0 to re-enable.)

getpos
(Creates 2 commands in the console. Copy+past the commands back into the console to teleport back to the spot you used the command. Useful to not have to walk back up to a high places to practice something over and over.)

give [item]
(Gives the survivor the item. For a list of items write out give in the console and then use the up and down arrows to scroll through the possible items. Example give knife.)

sb_takecontrol [survivor name]
(Gives you control of a different survivor.)

cl_showpos 1
(Puts a position and velocity indicator on screen. Use value 0 to disable.)

showtriggers_toggle 1
(Allows you to see invisible triggers. Use value 0 to disable.)

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Thanks for watching. Your viewership is greatly appreciated. Au revoir.

[svideos]

Author's notes:

This was an overview of most advanced movement techniques. There's still others possible but not covered in this video. Here are the techniques and reasons why:

The Animation Cancel movement technique isn't covered because it was a bug in the initial release of the game that has been patched for years. I want this video to be up-to-date. Everything shown off should be possible for everyone watching to do as of the date the video was published. To go intro greater detail the movement technique was performed by rapidly switching weapons while stumbling and it allowed survivors to cross large gaps.

This video focuses primarily on survivor movement techniques. Movement tech specific to special infected was not included. I feel it would be better to put SI movement tech into a separate video. There's enough to cover to have such a hypothetical video all to itself.

Movement techniques only really possible to perform with external tools and frame-advancing the game (TAS, Tool-Assisted Speedrun stuff) are not included. You can jump off of grenades shot by other survivors and bounce off of throwables and other obscure stuff like that. It's interesting but not exactly something you'd do out of the blue. Additionally, I never saw this project as an in-death speedrunner-specific guide. I suggest anyone interested in learning about movement techniques specifically for the use of speedruning Left 4 Dead 2 look elsewhere as I'm sure there are better guides made for that purpose.

Other Author's notes:

Yes. I said bunny hopping in that spawn off of the fences should be “fluid” and not “fluent”. This is intentional. You must be like a fluid and continue moving as if nothing happened, like how water would move. It's a metaphor.

For clarity when I was talking about poorly performed bunny hops I was also demonstrating them. That's why the footage of me playing as Francis on No Mercy 1 contained poorly performed bunny hops.

It took me 1.5 hours to get the footage of crouch bunny hopping on the bridge on Cold Stream 3. It's really hard to do that technique. Strangely, despite it being easier it took longer to get the footage of me regular bunny hopping down the hill on Dead Centre 2 as Coach. It took 2 hours of constant retires.

With regards to the live-action segments of this video: The controller is fine. The trash was empty other than having a new paper-towel roll on the bottom. There was no actually spider on my deck. It was a skit to comment on why someone would stop playing the game without clicking the “take a break” button. My mouse is a G900 Chaos Spectrum. It's like a sports car; expensive, great performance but super high upkeep. Like every month it gets full of dust. And the battery only lasts a day and a half. I love the mouse but would not recommend it.

Oh yeah, the reason you can't spam jump inputs is because a small sort of internal cool-down. If you hit jump right before you should, even if you hit jump at the correct frames it will not register. Don't quote me on this.

Actually don't quote me on a lot of stuff. Like I made up half the names of these techniques. There's simply no documentation or the documentation is so poor that I can't say for certain names even exist for some of these. As far as I'm concerned there's no mutually agreed upon naming for the tricks as there hasn't even been enough people around talking about these tricks to have set-in-stone names. I apologize in advance to speedrunners who use different names for these tricks. It must be jarring to watch this video and see something you're already familiar with be called something different than what you internally already call it.

When I make videos like this I always try to capture footage from different parts of the game. The problem is: it is hard to find places with nice clear lighting. L4D2 plays a lot with visibility in its game design. Dark areas, foggy areas and visually nosing areas are everywhere. So in the end there's not many usable locations. Unfortunately the campaign “The Last Stand” is almost entirely dark areas. So it's rare that some footage in captured on it. All outdoor area on “The Passing” have a blurry rain effect. So they also don't look great. Basically all outdoor areas on The Passing are also unusable.

When I say "by crouch jumping while bunny hopping survivors can build speed faster and travel faster" I mean they allow for greater acceleration. The max speed is the same for both kinds of bunny hopping. You travel faster in the sense that you accelerated to a faster speed more quickly.

[Skinned_fried_n_cut_up_potato]

The take a break feature is such a good thing and I’m so sad it never caught on to be popular in other games

[DukeOfGumby]

Best spots to bhop for fun
- The hill slide after the motel in the opening chapter of Dark Carnival.
- The downward slope leading to kiddie land.
- Bhopping off the roller coaster drop in Dark Carnival and coasting over the 3 small hills before entering the tunnel.
- The destroyed highway leading to the graveyard in The Parish, and also the street leading from the graveyard to the safe room at the end.
- The very beginning of Death Toll, using the hill to bhop onto the broken bridge.
- The Last Stand finale. Fun but very deadly.
- No Mercy finale. As soon as you reach the rooftop try hitting the sloped platform and land on the ladder leading to the minigun. The game still thinks you're airborne until you jump off the ladder. Cool if you're playing on a server with a bhop counter.

There's so many good spots to eject from in every single campaign, but these are just the ones that stick out to me the most. After 1000 hours every time I see any sort of downward slope, my brain immediately tells me I have to bhop onto it for the speed boost.

[Majima_Nowhere]

I know strafe jumping as "air strafing" from tf2, and it's baked into my muscle memory so thoroughly that I try it in every game I play. Thanks, Source engine.

[dnnyrn]

My highest Crouch-BHop streak I can recall was 8 in a row. It's crazy how good people can get at it, watching speedrunners perform them flawlessly is mesmerising.

[rissole_dot_exe]

Great video, most people didn't know the ladder climbing trick. It's been very helpful for me, ever since i saw many speedrunners doing it.

Still bad at bhopping, but getting there with more practice.

[WaifuRuns]

crouching while bunnyhopping just makes it harder and does not increase speed, because you jump the tick you hit the ground you are technically always in the air and can gain acceleration from strafing the entire time, so the gap between jump inputs isn't indicative of any extra time in the air, its only useful when trying to clear gaps or bunnyhopping uphill because increased height is good for those types of things

[Bloxro_orxolB]

11:33 I found that out accidentally while playing tank run, got punched off the edge of the chapter 1 slide into the valley. Fully expecting to instantly die only to just land on the ground like I landed on a mattres

[aechangel]

I remember this very clearly but in the first Left 4 Dead if you continuously melee a mounted turret and jump on top of it and jump again it can create a super jump and each hit is like a charge, it even gets to the point if you hit the turret enough you automatically jump by yourself and you jump again at the right time you fly like Superman.

[dangerouslysafe]

You can even use the No Ledge Grab tech at the very start of the No Mercy campaign.
Simply go to the back of the roof, past the skylight, and drop down onto the level decorations to safely get down.
Be careful, as this can be a deadly drop if you dont do this correctly. If you succeed, you will have skipped the entire apartment of the first map, which is roughly over a quarter of the map.
The two popular methods to do this is by landing on a zombie's head next to a parked car, or having a friend drop down onto some boxes to become incapped, allowing another player to start interacting with them on their turn to cushion their fall.
However, long ago, the original method was to use the air conditioning unit on the opposite building to get down.

[killerofold]

I've been playing this game since it came out and didn't know half of this. Super informative! Thank you!

[longjohnsilverribs]

quick video suggestion, you should probably go over on how the bot survivors have a special AI depending on the character. sorta like how coach always carries a shotgun, bill usually carries assault rifles, ellis and zoey usually carrying snipers, and so forth. its a pretty interesting topic, especially considering how the survivors aren't supposed to have any gameplay differences

[Ilovetorisomuch]

Btw the fall damage reduction for rezzing teammates can be fully blocked if you spam it a lot midair. Also you can do it with defib unit.

[DannyCheezits]

crouch jumping in intended gameplay doesnt make you jump higher than regular jumping because the game automatically crouch jumps for you when your trying to jump up to a platform that a regular jump cannot reach, that's why you can jump up to the top of the vent on hard rain final even though you realistically wouldn't be able to

[skully.]

I still remember having to learn the ladder bit from way back in the day when I used to play CSS Zombie Escape.
every ladder section there'd be people flying to the top meanwhile zombies reach you in 3x the speed you're able to go up. was ridiculous.
after learning it though, my god. the amount of people you catch on maps like mirrors edge on zombie escape for CS:GO is insane.
flies on a glue strip. that is absolutely one of the most underrated movement tech's to my knowledge that exists in literally every source game.

that move along side strafe jumping is what allowed me to keep up with most bunny hoppers, even though I never could manage to nail it down myself.

[microsoftpowerpoint]

I know all of these but didn’t know the inner workings of the fall damage reduction ones. Crouch bhop is like 5x better downhill, kills you even sometimes

[Real_RUBBR]

Just watching the first 25 seconds, I can already say the quick ladder climb is a technique I used all the time when I played this game a ton. It was a super helpful technique and it's amazing how it's so simple to pull off, you just strafe into it in addition to climbing up normally and you get boosted up. This also works for special infected when playing Versus! And not only that, but I believe it also works for all source games, and not just L4D2. Notable examples would be games like Half Life and Gmod. I believe TF2 also would work the same way but it depends if that game has ladders, can't recall if it does.
14:41 I would like to note that getting over this van can be done without the help of a zombie but it's very tricky to pull off

[Korrva]

Wow, this is such a good video, everything is explained in depth for people like me who overthink everything, the footage helps show what you are talking about and you explain everything in a clear and concise manner, thank you for this video, super well done

[MattyyyBoiii]

Been getting back into Left 4 dead 2 with friends and more often than not it ends up as a one man survivor situation, alot of these movement techs have been a god send for clutch moments! Thank you so much for making this easy to follow guide ❤❤

[Lonslo]

I've heard of all of these, except mounted boosting. Seeing as how niche and impractical it is I wasn't missing out on too much