Transcript of How Speedrunners Completely Break Undertale

A question that people ask me quite often is how can you even speedrun Undertale? And on the surface, I can see the concern. It's not a game with any particularly enticing movement tech. Attacks in battle are on a timer, and it just kind of seems like it wouldn't lend itself well to speedrunning. Unlike the follow-up game, Delta Rune, there's no run button or attack grazing or seemingly many mechanics that you would expect from an in-depth speedrun. But what if I told you that because of just one single exploit, Undertale is actually an immensely technical, mechanically demanding, and extremely precise speedrun. Ladies, gentlemen, and gamers of all varieties. Allow me to introduce to you the one and the only, the Punch Guard. Okay, so most of you might not even know what this item is or that it's in Undertale at all. So today I'm going to give you the full story of the punch card and how one small joke gag item completely shattered this game into a million pieces like its name is Wing Gastra. This is the story of how speedrunners completely broke Undertale. Okay, so what even is the punch card? Most of you probably don't know this item even existed. And I'm willing to bet that most of you who watch my content didn't know it existed before I showed you that you could break the game in half with it. The punch card is a joke item that's given to you if you purchase nice cream from the nice cream salesman in Waterfall. You get one item per purchase and can exchange three punch cards to get a free extra nice cream. If you use the item from the menu, you get to look at the punch card, displaying the salesman's desperate attempt to get you to come back by guilt tripping you with a sad, "Please, please come back." And yeah, you'll bet your ass this worked on me the first time. I just wanted to see the ice cream guy be as happy as possible. Okay. It can also be used in battle to rip it up, which gives you plus six attack, but only if you have the tough glove weapon equipped. Funnily enough, when the punch guard exploit was discovered back in 2016, it was by accident. The person who found it just happened to have it in their inventory because they were looking into potentially using the tough glove on Asgore by ripping like five different punch cards in the fight. It didn't work. Anyway, it's the ability to look at the punch card in the overworld from the menu that's our main concern here. This item probably wasn't given too much attention in bug testing, and as a result, one very tiny mistake that Toby Fox made in the programming would cause the metaphorical dam that holds back the torrent of glitches to fracture. So, what's the problem here? In order to explain what's happening, I need to first explain how Undertale internally handles when you are able to move your character freely and when movement is restricted. It's all handled by an internal variable in the game called global.inact. It's actually very simple. If this value is set to zero, you have full freedom of movement just like normal. If this value is set to one or any higher integer, that just means whole number if you don't know, then you are not allowed to move. In order to show this, let's take a look at how the game handles a cut scene. You walk into the cutscene trigger, the invisible game object that initiates a cut scene. And that trigger object tells the game to turn your global.inact variable to one. This locks your movement. From here, the cut scene plays out in whatever way that's intended with whatever text boxes and funny, zany, quirky character moments normally happen. Then, once the cut scene is over, the game will set your global.inact value back to zero, allowing you to continue normal gameplay functions. So far, everything seems good. a pretty rudimentary system, but if you've played through Undertale before, you know that it works perfectly fine. Sometimes simple is best. However, there's one edge case that Undertale had to account for. In this game, you're able to press a directional input and the menu button at the same time to move and open the menu together on the same game frame. In order to make sure this doesn't break cutscenes, the game is not allowed to initiate a cutscene while the menu is open. This enables you to use this ability, which we call menu buffering, to move onto a cutscene trigger while opening your menu, which prevents the cutscene from starting. As soon as you exit the menu, the game will immediately initialize the cut scene on the next game frame, and everything happens as normal. You can try various things such as using items, calling characters with your phone, anything, and nothing will break this interaction. So, it's a good thing that there isn't any particular item in the game that would abuse this interaction to allow you to gain movement during any cutscene in the game, right? After all, Undertale is a 2015 role playing video game created by American indie developer Toby Fox. The player controls a child who has f Oh, right. Yeah. So, how does the punch card break things exactly? Well, it's very simple. When you use the punch card from the menu in the overworld, the game importantly closes the menu, then buffers an instruction to be executed on the next game frame to display the joke punch card item on the screen. This displays the punch card and also sets global.inact to one. Then when you press Z or X to get rid of the punch card on the screen, the game always runs code that changes your global.inact value back to zero. And with this, that fractured dam from earlier completely shatters and releases a devastating flood of glitches and exploits straight towards the unsuspecting houses of the people who thought Undertale is devoid of mechanics in a speedrun. Again, importantly, outside of particular instances, the game only locks your movement during the cutscene initiation, giving you free reign to do anything you want. This allows you to skip through cutscenes and even skip entire boss fights. Muffet Metaton. I have absolutely no idea who you're talking about. Undy. Well, we can't fully skip her, but we can skip two of her phases. And hey, wait a minute. Did I just teleport with the punch card? I thought it just skipped cut scenes. Well, the party is only getting started. But first, I need to tell you about the sponsor of today's video, Factor 75. How did you get in here? 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And with this, I'm actually preparing one right now as we speak. All you have to do is unpackage your meal, place it in the microwave, and in just 2 minutes, you have a delicious meal ready to go. The directions are so simple, even an Undertale fan could read them. Okay, we both know that's impossible. So, if you want to try this out for yourself, head to factor75.com or click the link below and use code 50shay to get 50% off plus free shipping on your first Factor box. That's code 50shay at factor75.com to get 50% off plus free shipping on your first box. Thank you to Factor for sponsoring today's video. So, when does chapter 3 come out? The punch card allows you to seemingly teleport through rooms by doing what is known as a wrong warp. The punch card can skip all cutscenes. And you know how in Undertale when you walk up to the edge of the room, there's a screen transition event into the next room. You know what those screen transitions are? That's right, cutscenes. Screen transitions are handled by trigger objects just like cutcenes are. Meaning they're vulnerable to the unbridled wrath of the punch card. The only difference here is that instead of setting global.inact to one, they actually set it to three. But this is more for internal game organization than anything else, it's treated basically the exact same way in a practical sense by using the punch card while positioning yourself perfectly. You can gain movement during a screen transition event so long as you never walk back into the trigger during the screen transition. More on this in a moment. The game gets extremely confused. You are not where you're supposed to be. In order to not crash the game, instead of appearing where you're supposed to, the game will spawn you in at the next room's default point. This is a completely arbitrary location in a room that is set for debugging purposes. You're actually already familiar with what a default point is if you've played the game. It is the location you will appear in if you load a save file in a room. This is how the game places you right beneath a save point when you load your save file normally. These are set for every room because while debugging, you need to have the ability to start the game in any room. So Toby just placed them wherever for the rooms that don't have save points in regular gameplay. Because we're eternally cursed to not have a run button, wrong warping into rooms can save a ton of time in speedruns and even enable very notable strategies such as skipping this entire phase of Undyne's fight by getting through the room faster than intended. Earlier, I mentioned needing to never walk back into a screen transition after using the punch card in order to successfully wrong warp. This can be achieved by holding any perpendicular wall because this game's movement code works in very strange ways. By holding a wall, you're able to initiate the screen transition event seemingly without moving. Because the game sees the attempt at moving into the trigger, but doesn't actually move the player because of the wall. However, the attempt at movement is actually enough to initiate the screen transition. So, holding a wall is a surefire way to ensure that you only touch the trigger for one game frame and don't accidentally walk back in. One huge limitation of wrong warps, though, is that they have a very tight timing window in addition to the pixel perfect positioning requirement. Here's the thing that makes them dangerous. I mentioned earlier that the punch card originally forces your global interact to be one when you use it. The thing is is that if you attempt a wrong warp and aren't able to close the punch card in time, this code will haunt you into the next room. The screen transition event will erase all game objects from the previous room, including the punch card. But because it was never properly closed, global.inact will be set to one forever with no way to change it. Meaning that you will stand there with no way to move until the heat death of the universe. Forget Sans's special attack. This one is much more terrifying. This is why you'll see Undertale speedrunners quickly mash the interact button whenever they do a wrong warp to avoid getting stuck in place forever. Hopefully, by now, even the most stringent of doubters can see that this exploit completely changes how the game is played in a speedrun. Every single cutscene skip and wrong warp are all pixel perfect, requiring perfect memorization of every single cut scene trigger in the game, or at least the ones that are actually worth skipping. Wrong warps are scary and require tight timing windows on every single one to avoid soft locking, but these are just the first layers of the Undertale speedrunning iceberg. When the punch card exploit was originally discovered in early 2016, wrong warps were found shortly after, but the technique would be further researched and honed over the years to enable even more trickery. Some of it getting very, very complicated. One addition in our bag of tricks is the text overflow glitch and by extension the overflow wrong warp glitch. So, what's text overflow? Well, it's actually pretty simple on paper. You know how in this game when you interact with something, a text box shows up? You know, the most basic breadandbut gameplay function of Undertale? These two are cutcenes. Remember how I mentioned earlier that there's one buffered frame between the punch card closing the menu and appearing on the screen? Normally, this is where the cut scene initiation happens. But in non- cutscene situations, this is a fully interactable frame, meaning that you can actually move one pixel in any direction. But more importantly, you have one single actionable frame to interact with objects. This causes their text to appear on the screen and then immediately after the punch card appears. Because you can close the punch card with Z, which does nothing to a text box as long as the text is still scrolling. You can then walk around with a text box on the screen, which reveals that the text box itself is positionally tied to the camera, but the text inside the box is actually in the overworld itself. So, you get this funny effect where you can just leave the actual words of the text box behind. After all, we're Undertale fans. Reading isn't exactly in our wheelhouse. So, what can you do with this text box? Well, I explained earlier how the end of cutscenes set global.inact back to zero. And text boxes are basically cutcenes, right? So, they also set global.inact back to zero when you close the final piece of text in a text box. Everybody, I'd like you to meet punch card 2. That's right. The end of the text boxes can be used as a makeshift punch card. Cutscenes do not wipe away already existing text when they start. So, if you overflow pretty much any object's text and walk into a cutscene, you can just quickly close it for the exact same effect as using a punch card. This removes the pixel perfect aspect from quite a few different cutscenes, though you can't do it all the time because it requires a frame perfect time input, and it's usually slightly slower to do in speedruns. However, they're a pretty consistent trick for new runners to use. And I famously took several world records back in the day by still using text overflows in many places because I just valued the consistency of them. Oh yeah, they can also be used to wrong warp much more safely as well by doing the exact same setup because you're actually hitting the screen transition with your global.inact already set to zero with the text box on the screen. You don't run into the soft lock issue because you don't have to worry about closing the punch card quickly to avoid global.inact staying at one forever. So yeah, between all the pixel perfect precision, memorization, and frame perfect inputs, I'm pretty sure it's actually a pretty mechanically interesting game after all, the development of the punch card exploit over the years even led to some other glitches being found, such as the seaggrass skip trick to skip this cut scene here without the punch card. Uh because for some reason, this one cutscene and only this one cutscene has a four-frame initiation period instead of one frame, letting you actually have the time to use the cell phone as a makeshift punch card. or this trick to skip the dummy in the entire room in ruins, which was just discovered last year. This game is almost 10 years old, and we're finding skips that save 30 seconds. Undertale is nowhere close to being completely solved as a speed game, and I'm sure further developments will continue as time passes. I hope you all enjoyed learning the in-depth story of the absolute insanity that is the Punchguard Exploit, and how it has completely transformed Undertale's identity as a speedrun, and also all of the glitches within it. Thank you so much as always and I hope you have a wonderful night and take care. [Music]