Stop Bugging Me
Bugs that make and break the games we love
June 07, 2017
Infil blackadde

Some Bugs Will Define a Game

We used our previous category to discuss bugs that are terrible and clearly should be fixed immediately if at all possible. But really, we aren’t here to discuss those bugs too much... they are mostly just an introduction to a more interesting part of the discussion; bugs that kept the game playable, but drastically changed the main strategy for success. Despite these bugs being very unintentional by the developers, it is actually much less clear whether they were bad for the game overall or not.

Yeah. There are plenty of games that we can take a microscope to, especially from the era where patches weren’t really viable. The most important one to start with is probably just the concept of ‘cancels’ in the Street Fighter 2 series.

Street Fighter II - Cancels

Yes, I think this is the quintessential example in this category, and most people who know a little bit about fighting game history probably know that the entire notion of a “combo” as we know it today stemmed from a system in SF2 that was intended to make special move inputs easier. Instead, the game accidentally allowed normal attacks to be canceled into special moves, bypassing the normal’s recovery entirely. This unintended side effect paved the way for 25 years of new and cool fighting games.

Canceling a normal into a special move was unintended behavior in Street Fighter 2.

Street Fighter 2 started out as a brawler, right? In the same vein as Final Fight. So the concept of ‘hitstun’ and ‘chains’ definitely existed for the team as they worked on development, since beat-em-ups had that sort of thing back then in the early 1990s.

Cancelling a normal into a special move to make special moves easier to do highlights an important thing, actually - many (almost all) of the bugs that affect gameplay in fighting games revolve around translating intended actions into actual game logic. People aren’t robots, and we don’t execute perfect quarter-circles or press down buttons on the exact frame we finish motions.

Street Fighter 1 was notorious for special moves that were virtually impossible to execute. The input requirements were so incredibly strict that the game was no fun to play. It is well documented that Capcom knew about this and made loosening the inputs a design goal in Street Fighter 2, and there’s no doubt it tends to be the source of a lot of unintended side effects in games.

Besides combos, which I think most people agree are super rad and the genre would look a lot different today if Capcom decided to fix the unintended effect back in 1991, I think the other most interesting bug involving cleaning up poor inputs happened in Capcom vs. SNK 2, a truly game-defining bug called “Roll Cancel”.

Capcom vs. SNK 2 - Roll Cancel

For those of you who weren’t around for the Dark Ages of Capcom (bless your souls), you need to know something about how CvS2 worked - first, that you were able to select ‘grooves’ for your team, and second, that only some grooves had access to a roll mechanic.

Only C, N, and A groove had rolls. The others (S, K, and P) didn’t. A roll was executed by pressing LP+LK and made you move forward with invincibility for a set period of time. However! In their infinite wisdom, Capcom allowed you to cancel rolls in their first 3 frames into a variety of other things, such as special moves or super moves. The bug works like this: you input your roll, then immediately do a special move, and instead of just negating the roll, your character just does the special move with the full invinciblity you would have had if the roll completed.

Iori uses an invincible roll canceled Rekka to get through Hibiki's attack. (source)

The end result essentially boils down to this; if you played a groove with a roll, every single special move could act like an invincible DP. Every single one. While rolls could be thrown (and therefore roll cancelable moves can also often be thrown), the invincibility from the roll was added to your base invincibility, so if you did a move such as Ryu’s hurricane kick, which was off the ground and therefore unthrowable, you now have a fully invincible hurricane kick.

Plus, it was quite easy to space special moves outside of throw range, so in practice, throwing roll cancel moves as a counter strategy just wasn’t very viable. You had to deal with Blanka doing roll cancel Electricity, an advantaged-on-block move that did 10% chip and crushed your guard, except now it is fully invincible too. With good execution, people could reversal with safe-on-block roll canceled special moves and it was extremely difficult to stop.

This bug changed everything about how CvS2 was played. I think the main thing to talk about first is that, for intermediate players, if you didn’t know about roll cancel and your opponent did, your road to victory was massively uphill. There was now a strict barrier to entry to play the game; you must learn the execution to roll cancel (almost) every neutral special move you do, try to build a team around a non-roll groove, or go play something else. Do you think that’s fair to say?

The game definitely revolved around roll cancels. There are characters that work in non-rolling grooves, too, like K-Cammy or K-Geese, but honestly they can’t compete with things like A-Bison (invincible Psycho Crusher / Knee Press and Custom Combos to boot). Tournaments were rife with Vega players RCF-ing through fireballs or invincible Honda 100-Hand-Slaps punishing people who thought they could press a button.

Blanka and Kyo both roll cancel moves at the same time. Eventually, invincibility wears off and one of them hits, but it looks funky. (source)
I think the other question is this: is the game better, or worse for it? That is, would the game be less interesting without roll-cancels? Does it give characters that would otherwise be useless a chance to compete again? Is the barrier to entry merely high, or too high?

It’s a really interesting question, one I’m sure CvS2 players were grappling with a lot back in the day. We have the benefit of hindsight to look back, but because CvS2 was a prime game during the Dark Ages, they really had no choice but to suck it up and play, regardless of what they thought.

I think the first thing to note is that the execution for roll cancel is actually quite tough. It is effectively kara-canceling a roll into a special move, but if you completed, say, your quarter circle input completely before you input LP + LK for the roll, you would often just trigger the special move raw. Thus, it required a certain finesse to roll cancel reliably, and let’s not talk about the difficulty of roll canceling rapid input moves like Blanka electricity or Honda hands. This means, though, that even very good players could mess up roll cancels in a match, and watching someone roll cancel with ease was something that I found pretty entertaining and added a certain charm that CvS2 might otherwise not have had.

As for tiers, the top tier in CvS2 is very strong, and roll cancel made them even better, but I believe roll cancel actually gave several lower or mid-tier characters a chance to survive against them, right?

My understanding is that it kind of helped characters who would otherwise really struggle against the top tiers some tools - C-Guile (RC Sonic Boom), C-Honda (RC Hands and RC Headbutt), N-Iori (RC Rekka), and C-Chun-Li (RC Spinning Bird) for instance. But eventually everyone got smothered by things like A-Sakura, A-Bison, A-Blanka, and C-Sagat anyways, since they were not only amazing to begin with, but also benefited greatly from roll-cancels themselves. Then again, I’m not a CvS2 pro, so maybe others would disagree.

Chun challenges a poke with invincible, safe-on-block RC Spinning Bird Kick, but Bison just paints her fence anyway. (source)
Personally I find it interesting but I also know that it would never fly today, and for good reason.

So, if you’re Capcom and you release CvS2 as a brand new game today, and you find out there is roll cancel in your game, do you immediately patch it? I think the answer has to probably be yes, but because we have the benefit of history to look back on, I’m not so sure that non-RC CvS2 is more interesting than RC CvS2. Removing roll cancels probably makes a notoriously slow game even slower, and perhaps the top tier gets even more lopsided. I think this is a really challenging case study.

I agree with that. It’s definitely not as simple as ‘this shouldn’t be part of the game’, but it isn’t totally a benefit, either.

To me, it really just shows the difficulty of making fighting games, and how so often the rules that define how a game is played are completely different from what the designers intended. Sometimes that manifests itself in bugs, but often it can just be a powerful overlooked strategy. The decision on when and how to patch these things, if they should be patched at all, is something I find really fascinating and I definitely don’t think there is an easy, or consistent, answer across all games. But perhaps that is a blog post for another time!

Marvel vs. Capcom 3 - DHC Glitch

Well, here’s an example of a similarly game-defining bug that’s more contemporary: the DHC glitch in the original release of Marvel vs Capcom 3.

For those unfamiliar with the glitch, it worked like this: place your opponent in a ‘capture’ state, then somehow DHC (‘Delayed Hyper Combo’ - cancel one hyper combo into the next character’s hyper combo), and miss the hit. The opponent character spirals up into the air and comes down slowly, allowing you to continue your combo. Except, instead of continuing the combo scaling and hitstun decay (intentional mechanics that prevent you from doing absurd amounts of damage in long combos), both of those things get zeroed out once you begin to hit them again. It’s basically an inescapable reset, letting you do way more damage than was intended by the developers.

Magneto 'captures' with HyperGrav, causes Chris to spin out, then DHCs into a non-hitting Wolverine super. All damage and hit stun scaling get reset. Watch the difference in damage between Magneto's (scaled) hits and Wolvie's (unscaled) hits. (source)
The DHC glitch was ubiquitous in tournament play. It greatly affected both team viability and team orders. Personally, it made things like my Magneto / Arthur team sort of work - capture with Hyper Grav, start Magnetic Tempest, DHC into Arthur’s armor and then continue the combo, leading to a kill by a character that usually did very little damage.

Like CvS2 roll cancels, it allows for otherwise awful characters to have a role to play if they can initiate / benefit from the glitch - but, as before, does it make the game more interesting or fun? Does it stratify the top and bottom tiers even further, or does it balance them out?

It’s interesting, because we have to think back to the climate around Marvel when Marvel vs. Capcom 3 was first released in early 2011. The modern era of fighting games was still in its infancy, and most of the people excited for Marvel 3 were old school Marvel vs. Capcom 2 heads that were itching for a modern take on their favorite game. As such, what they were looking for in Marvel 3 was just more of what they loved from Marvel 2; fast-paced gameplay with relatively few touch of death combos, lots of resets, and very high execution.

I think the DHC glitch was very antithetical to that. Suddenly they had a very easy answer to kill a character and it only cost them 2 bars. I think this is one of those examples where the end result is so strong that it can remove creativity from a team. Maybe you had a team you really liked, with a high-execution, flashy 2-bar or 3-bar combo that brought the opponent near death, and you just needed one reset to kill them. But don’t worry, you had all these cool multi-layered mixups planned to get that kill! That all doesn’t matter once you know about the DHC glitch. You just do the easy, undroppable combo using 2 bars, kill, and move on.

Vanilla Marvel 3 was an extremely high-damage game already, and DHC glitch kind of just sealed the deal. It became touch-of-death: the game. So I agree that on balance it kind of messed with the game in a way that wasn’t really beneficial in the long run - although the game got supplanted by Ultimate Marvel vs Capcom 3 so quickly that we’ll never know how it would have shaken out.

Ultimate Marvel vs. Capcom 3 - TAC Infinites

Speaking of UMVC3, there’s another glitch in that game that affects things in the same kind of way: TAC infinites.

In this game, while you’re doing an aerial combo you can perform a Team Aerial Combo (TAC) and switch to your next character by pressing a cardinal direction + the S button. The screen freezes and you tag in the next character slot, but if your opponent ALSO guesses the direction and pressed S at the same time, they break the combo. So it’s a 1/3 guess - TAC up, down, or side. (Actually, it’s worse than 1/3 because you can also just reset them by punishing their attempt to break the TAC, but whatever).

It’s kind of complicated, but basically once you TAC into your next character, hitstun decay (the system in the game that prevents infinite combos) doesn’t kick in until you touch the ground in a neutral state. So as long as you avoid that, you can juggle your opponent forever. I hope that makes sense.

Hit stun scaling is very aggressive in Marvel 3, so in order to make sure that the (relatively long) TAC animation always connects as expected, the game temporarily disables the hitstun decay. Because they plan to turn it back on once your character touches the ground, they figured nothing bad could happen here, but like most fighting game developers, they were very wrong.

As it turns out, if you land from your TAC combo while an attack is active, and then immediately jump again with precise timing, the game thinks you never actually returned to a neutral state! So the hitstun decay never gets turned back on, and you can continue to loop this until a character dies.

Dr. Doom does as much of the TAC infinite as I can fit into a 15 second gif. The key moment is when Doom touches the ground, but manages to jump and keep the combo going. That shouldn't be possible. (source)
TAC infinites were actually not found immediately at UMvC3’s launch, like most bugs in this category. In fact, the first well known instance of someone doing a combo that involved the start of this glitch was Marlinpie, perhaps the most famously swag tournament player. He also managed to do some versions of the combo where nobody has any idea what’s happening, but it’s insanely cool to watch!

Later, the bug would become much more researched, and people would actually prove that, yes, these combos are not too difficult to set up in real matches. And thus, the strategy of building your team around TAC infinites began. Fortunately for most people, Dr. Doom strongly benefited from this glitch, and most teams had him second already anyway! Hah!

Texas player Jan performs the first multi-rep TAC Infinite in a tournament setting at Evo 2012. (source)

Yeah - teams with Dr. Doom benefited immediately because he was a) an extremely strong assist character, and b) almost never point or anchor anyways, so he was a natural fit for TAC infinites.

So the thing about this is, lots of characters have TAC infinites now, and they all kill (or in the case of say, Dante, at least stall the game):

Dante's TAC infinite takes forever because it does so little damage. (source)
So what this means is, nowadays many teams have infinite damage potential if they successfully TAC into their second character. Which is the most there is. In a way, this levels the playing field. Some characters in Marvel have awful damage output, but are otherwise fun to play, and TAC infinites ‘fixes’ their damage problem in a roundabout way. Damage among good characters is still so high that often all the top tier characters would kill you on the first hit anyways, so the glitch only marginally benefits them by comparison.

I think that is a really interesting point about many of the bugs in this category; they are often unintentional but interesting fixes to design problems the team didn’t even know they had. Often, they can ‘fix’ lower tier characters to compete with the top tier, thus diversifying a game’s roster. And I think this has to be taken into consideration when talking about game-defining glitches like this. To what extent does this glitch ‘fix’ an issue with the game? It’s very often not a simple answer, since the glitch adds negatives with its positives, but I think the conversation has to start there.

One thing I particularly like about TAC infinites is that they are executionally challenging and require good situational awareness. You have to have TAC infinites planned for all directions of your tag (up, down, side), at various heights on the screen, and at various distances from the corner. It is still very common to see these dropped even by the world’s best players. So while the combos themselves are often rote and long, sometimes it can be exciting to see if a player will drop the execution in the clutch.

Yeah, it definitely isn’t strictly a negative bug, despite it being totally unintentional and super obscure. It adds some strategy to your game (what character do I put behind my point character?) but also happened to be stuck behind a stupid rock-paper-scissors mechanic (TACs themselves) and some of them take so long to finish killing that even players who can do them don’t like them.

Ultimate Marvel 3 has not been patched since right near its launch, so there are definitely lots of Marvel fans and top players discussing what they would like to see changed in a theoretical patch for the game. I do believe most of them do agree that TAC infinites should be removed, and I think there’s a pretty good case for that just based on spectator boredom alone. If it came with other changes that buffed up some of the lower tier characters, thus addressing the low damage concern you mention above, then it seems like a good change for the game. We’ve already gotten all the hype we can out of Marlinpie’s combos already.

Street Fighter Alpha 3 - Crouch Cancel Infinites

Interestingly, this is not the only bug that requires tricking a game into thinking you haven’t returned to neutral after landing from a jump. Street Fighter Alpha 3 (known as Street Fighter Zero 3 in Japan) has a famous bug called “crouch cancel infinites”.

Vega does a crouch cancel infinite. I skipped the gif ahead to save you 30 seconds of jump light kick. (source)
The bug involves the game’s custom combo mechanic available to players who choose the “V-Ism” system on character select. Normally in Alpha 3, players will air reset out of combos if sufficient hits have been accrued, or if the character returns to neutral on the ground. Due to a quirk in Alpha 3’s juggle system, if you juggle your opponent into the corner during a V-Ism combo, the next hit after they reach the corner will grant an especially long juggle window. This, in theory, is supposed to let you get one more beefy air attack of your choice before you return to neutral and the combo ends.

Except, if you land from your jumping attack while holding down (i.e., crouching), and then jump again before the 4 frames of your crouching animation have completed, you will completely bypass this neutral state. You will be able to jump again and hit the opponent before they reset, and this special “long juggle” state will never end! As long as you can keep this loop up, you will be able to do an infinite combo.

It’s actually quite a bit harder than it looks; every jump must be crouch canceled within 4 frames, and the normals that you use to keep the opponent bouncing in the air must be input at a very specific height. It’s very common if you watch Zero 3 footage to see good players attempt these and mess them up.

CC Infinites eventually really dominated Alpha / Zero 3. Even though there are characters without infinites that are very good, eventually you’ll just get hit by Cody or Karin or whatever and die. So they really affected the competitive balance of the game once they were discovered. I think that if the game had been released today, it’s clear that it would have been patched out with time, since it doesn’t seem to add much to the game’s variety. Situations where you take away control of the opponent’s character (via keeping them in infinite blockstun, hitstun, etc.) are almost always a negative, especially when it just ends the round or game, and doubly so when it takes a long time.

Yeah, I think this is one of the clearer examples of something that just… probably wasn’t healthy for the game. You started the round with full V-Ism gauge as well, so you could kind of threaten with it immediately. And a lot of Alpha 3 matches ended up either going to time out, because the infinite took so long but didn’t do enough damage to kill (but enough to get a life lead), or the opponent spent 50 seconds watching his character get hit by a staple gun, losing 0.5% of his health per hit. Not really a good recipe for a spectator friendly game in the modern Twitch era.

Street Fighter Alpha 2 - Valle Custom Combo

We should also quickly mention another famous glitch from the Alpha series, this time from Street Fighter Alpha 2 (or Zero 2). This one, called the “Valle CC”, is famously named after Street Fighter legend Alex Valle, who rose to prominence in the Socal scene in the mid to late 90s. This one is much easier to explain: when you activate a custom combo (CC) in Alpha 2, you can hit your opponent with a free low attack, providing they were not already blocking low before your activation. The game simply does not let them transition to a crouching block fast enough after your activation, making the attack unblockable.

Once Ryu activates his custom combo, because Guy was not already crouch blocking, he is guaranteed to get hit by a low attack. (source)
The famous story goes that Valle had found this glitch while playing casuals with a local friend, and Battle by the Bay, the tournament series that would eventually become Evo, was coming up. His Norcal rivals, particularly Street Fighter legend John Choi, would be attending. Valle kept this technique largely hidden until he could use it in the finals of the event against Choi. As expected, Choi got hit by the technique numerous times at first, until he realized what was happening and used it on Valle in the same tournament set just a few moments later! Now that’s adaptation.

Yup. Old games are weird. I think the lesson we can take away from this category of bugs - ones that define their game, but don’t quite ‘break’ them - is that not all major bugs lead to degeneracy in gameplay, but it’s a fine line to walk. Sometimes, they even add some flavor or strategic depth to the game, despite their obvious negative qualities.

Yeah, when glitches like this surface in modern games, I think the obvious reaction is to just patch them out immediately. However, we’d be a bit remiss to not think about how the era of not patching games has shaped where we are today, and the important lessons we’ve learned along the way about how games are made and what makes a game fun. Sometimes, a bug like SF2 combos will completely and wholly shape a genre moving forward, although I think in the modern era of game development that is considerably less likely than it was 25 years ago.

I agree that it’s a super fine line to walk with contemporary games, though. You don’t want to alienate a big chunk of your audience who doesn’t like a bug by keeping it in, but you also don’t want to remove interesting gameplay (or upset a different subset of people, most likely) by taking it out. It’s a difficult, nuanced conversation and perhaps people who are new to fighting games and are upset at much less severe bugs in their modern game of choice would be interested to learn just how foundational some classic bugs were.

Other genres of games have bugs that work kind of like this too - they kind of help define the game in a fundamental way and despite their inelegance they added a charm or flavor that fans often really grew to appreciate. Some examples include Halo 2 Super Bounce, Counter-Strike Bunnyhopping, Quake 3 Strafe Jumping, and Starcraft 1 Mutalisk Stacking (a technique noted Starcraft personality Day9 also likes a lot).

Yep, in all these cases, you were forced to learn the technique to survive, and while many people likely found the bugs stupid and quit the game, the lasting community around these games have come to love them as a hugely important aspect of competitive play for their favorite game. In some cases, sequels to these games removed the bug in question, and it made the game less interesting to many fans!

Okay, let’s move on to our next category of bugs - those that can heavily influence gameplay, but only on a semi-regular or character-specific basis.

Back to the blog index.

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