January 17, 2008

Combat Cancelled

Normally I would not write this kind of article but since it is a new year and was sort of prompted by some God of War questions in the past and recently on Derek’s blog here I am. A lot of questions have always swirled around some of the attacks Kratos has in his arsenal, namely the L1+ Button special moves. The questions usually stem from the inability to “Cancel” these moves thus rendering them useless so to speak. Instead of just defending those moves I am going to examine the entire concept of move cancelling from its early days in fighting games to its cross pollination with action adventure games.

Let’s start with the grand daddy of them all Street Fighter 2: World Warrior. There is a legend that one day during early tests of this game out in California a guy named Tomo Ohira was destroying people in the game with some crazy technique where he could link certain moves together that normally could not be linked together, thus creating a combo by canceling! Ok so I was a kid in Ohio when I heard this so of course I believed it because Tomo Ohira was the best American Street Fighter player at the time. However, later I learned that this was a “bug” in the game and known by the development team in Japan but they thought it was too hard to execute to be useful so they left it in the game. Well it happens that the “bug” was the birth of the Cancel and Combo! The best example is roundhouse sweep cancel to fireball with Ryu, which I view as the catalyst for many other Street Fighter cornerstones such as zoning and footsies. So you get the point Street Fighter started it all and I just wanted to share some history so now onto how this affects action adventure games.

First let’s define a cancel just so we are all clear; a cancel is the ability to end one animation early by beginning another animation when the user manipulates of a series of branches in an animation tree through inputs on the controller, talk about clinical. Without diving into all the nuts and bolts of a combat system I am going to breakdown cancels by type and method. Cancel types fall into 2 core groups; “Partial Cancel” and “Complete Cancel”.

A “Partial Cancel” allows an animation to be canceled at specific windows during the animation. The two most common conditions for a “Partial Cancel” are pre-hit frame (the animation can be cancelled any time before the first frame of the hit) and post-hit frame (the animation can be cancelled any time after the last frame of the hit).

A “Complete Cancel” allows an animation to be cancelled at anytime during the animation. Of course I am generalizing and there are special nuances that exist in certain games but for the most part these conditions are used 99% of the time.

The methods I am going to cover are the ones that account for the bulk of all games and they are "Buffer" and "Instant".

The "Buffer" method stores and executes the user’s command when the cancel window is valid. The "Buffer" method in a well-designed game can be cancelled itself with other commands before the cancel window is valid to ensure the highest quality of responsiveness.

The "Instant" method accepts and executes the user’s command on the frame of input when the cancel window is valid. The "Instant" method allows the player to delay the timing which adds to the overall responsiveness of the game.

Now for an example: We have an animation called “Square01” that is played when we press the Square button, the animation is 60 frames long and has a hit frame window from frame 15 to frame 20. (see the pseudo combat scripting below)

//60 frames
Animation = Square01

//hit frames
On = 15;
Off = 20;

//attack cancel
Anim = Square02; Button = Square; On = 0; Off = 21; Method = Buffer;
Anim = Square02; Button = Square; On = 21; Off = 60; Method = Instant;

//block cancel
Anim = Block; Button = L1; On = 0; Off = 60; Method = Instant;

What does all that mean you might be asking yourself? Notice the On/Off parameters, these are frame values and determine the range of the cancel window. The method parameter assigns the type of cancel, see the definitions above if you have forgotten already. We can now determine that “Square01” can never be cancelled Pre-hit frame with the square button since the frame range is 0-21, instead the square button can be buffered until Post-hit frame 21. We can also determine that “Square01” can be instantly cancelled at anytime Post-hit frame since the frame range is 21-60. It also says that the L1 button can cancel “Square01” instantly at anytime thus making it a Complete Cancel since the frame range is 0-60. If this made any sense at all, now imagine doing this for every possible animation a character has in their arsenal and how they relate to gameplay systems such as parry, block, counter, walk, run, jump, double jump, magic, throw, reactions, etc… To give you a little perspective, Kratos had roughly 4000 cancel branches in God of War 2 with many more parameters to be tweaked per cancel branch.

Bored yet? I promise to stop being technical right now!

What can a well-implemented cancel system add to a game? First off it usually determines if a game has that lagged out feel or is crisp and super responsive. From a defensive point of view it creates that feeling of a best offense is a great defense. The player can just bang with the enemies but guard cancel to generate new holes in the enemy’s game. Guard canceling in Soul Calibur is super fun because it has Pre-hit frame canceling only which allows the player to fake attacks creating a whole new layer of mind games. Street Fighter 3 and Marvel Series make great use of super move cancels, which looks flashy in the traditional Capcom vein while promoting heavy offensive style gameplay. Also you might note that cancels are so good in some games that they actually require meter to perform like in the Guilty Gear series. It's almost impossible to factor all the changes one type of cancel system can have on a game, one such case is CvS2 and the infamous "Roll Cancel" where certain moves can become invincible based on a cancel bug, talk about an oops. Ultimately though it comes down to fun vs. abusiveness but mostly a great cancel system equals depth and allows the player to be super creative which helps increase the fun and sense of achievement.

Here some thoughts on the top three games in the action adventure genre, in no particular order Ninja Gaiden, Devil May Cry, and God of War. Placing the game I worked on for nearly 4 years in the top three will surely drum up some interesting comments, can’t wait… this is why I do not write about the games I work on if at all possible.


Ninja Gaiden is very strict when it comes to canceling so strict in fact that not a single animation that I am aware of can be canceled Pre-hit frame. I feel this is a great rule when trying to build a solid foundation for the combat gameplay but also adds to the difficulty. The player knows when they press a button to attack it must complete its hit frame before another animation can take place. Here is a funny thing about that rule, it is so true that the player cannot even pause the game because they could swap weapons and cancel before the hit, don’t believe me try it out. The game is made to be hardcore and for the hardcore so they use rules that help establish a fair play field if the player is willing to learn the system to the point of flawless execution. I applaud Itagaki and Team Ninja for their effort and contribution to the genre!


Devil May Cry follows many of the same rules that Ninja Gaiden does but in true Capcom fashion they have to drop the style bomb all over rules and add in some broken stuff just for fun! The main cancel system that drives DMC is the alteration between Melee and Projectile attacks. I believe that all Melee attacks are all Post-hit frame cancels and the Projectile attacks are governed by the rate of fire. Since there are between 5-6 Melee and Projectile weapons the combinations create for quite the learning curve and when you add in the styles the possibilities are staggering. Depth is the result but in a much more chaotic and flashy manner then the technical presentation found in Ninja Gaiden. Nevertheless there is no doubt that DMC is an acquired taste from the dark moody art to wise cracking cocky Dante himself but when you get it, you get it and the rabid fans for this series will always let you know they get it!


God of War unlike the other two games allows for many Pre-hit frame cancels and incorporates several of the methods found in the other two games. The main difference is that it is not trying to be a hardcore game from neither a technical nor flashy point of view. It’s just smash and kill fun with some goodies tossed in under the hood for the fans of the other games that gave us a shot while they waited for the next installment of Ryu’s or Dante’s saga. The rules for canceling are all over the place but for good reason, our intended audience does not want to learn the techniques, they just want the game to play the way they think it should because combat is not the only focus unlike the other two games.

So what about the L1+Button specials and why they cannot be cancelled? The moves in question are by far the strongest damage inflicting attacks Kratos has that stem from a simple button command, they hit many creatures at once in most cases, leave the creature in a vulnerable state, or in some cases both. The moves also serve as a little flash and make beginners feel really powerful when they see the blades spinning all over the place. Like I said before the other games only have Post-hit frame canceling and use this to teach the player, watch before you attack. God of War allows almost all of the basic attacks be cancelled anywhere including Pre-hit frame to make life easier on the player. The L1+Button specials possess enormous damage potential in certain situations and thus are not able to be cancelled until Post-hit frame for balance reasons (infinite lock down loops mostly). Moreover for novice players they are used to teach the concept of risk vs. reward without placing this burden on the basic combat which would make the game much harder for the average player. I know this can be argued from many different angles with regards to balancing but trust me I have heard them all and this was the decision we made but feel free to tell me how foolish we were anyhow.

At the end of the day you have to look at your intended audience and I think we captured our audience the best we could. To those that were left upset and disappointed because of 4 little moves in the game that cannot be cancelled earlier then I am sorry you missed a much greater experience.

It’s easy to say God of War is flawed and this that and the other but the fact remains that it is the only American action adventure game to ever get the attention of the Japanese. I grew up playing their games and wanted to make a game that felt like a Japanese game but played balls out like an American movie and God of War allowed me to do that. It is not perfect but it spoke to some people and that is all we can hope for as game developers.

I know one thing for sure increasing the amount of canceling in a game decreases the possibility of the game being cancelled!

Please feel free to ask any questions in the comments and I will try to answer promptly!

Thanks!

p.s. God of War has some serious fun with cancels, press square once then try any of the following if you don’t believe me.

Walk (Navigation) = Post-hit frame
Jump = Pre-hit frame
Roll (Evade) = Pre-hit frame
Magic = Pre-hit frame
Throw = Pre-hit frame
Guard (Parry / Block) = Pre-hit frame
Weapon Swap = Post-hit frame

17 comments:

Jason "Shirts" de Heras said...

Wow.

Flark said...

I switched tabs in my browser post-bored frame....


just kidding!

ortholomeux said...

cancel FTW!

Anonymous said...

"It’s easy to say God of War is flawed and this that and the other but the fact remains that it is the only American action adventure game to ever get the attention of the Japanese. "

Depends on your definition of action adventure. In my book, that includes Banjo, Crash Bandicoot and GTA. All of which made an impact in Japan.

Margalis said...

Thanks for the explanation.

The theory is all solid but I think the balance is off. One of the main things is that you face a lot of enemies at once and those enemies are more aggressive than in GOW1. That means any attack that you can't cancel that doesn't hit all around you it not very useful. Let's look at them:

L1+O: The animation for this lasts for literally 4+ seconds. Even if you aren't knocked out of it the later hits tend to be off-axis and miss.

L1+ /\: Again long animation, does not hit all around you, also tends to miss off-axis.

L1+[]: This one is actually useful in certain situations, mainly because it does hit all around you forming a protective barrier of sorts.

L1+X: Quick animation compared to others, useful.

So in short, while the theory is good I think how long the animation takes was not given the proper weight in balancing.

I'd be curious to hear if anyone knows for sure how often people use these moves. From reading FAQs and message boards my guess would be not very often. I could be wrong, but the slower L1 moves, while making sense on paper, seem basically useless.

Also because GOW2 removed the energy bars on bosses it can be very difficult to tell how powerful moves are in relation to each other. For example is L1+O any stronger than just doing a combo yourself? If so it isn't that noticeable.

Anonymous said...

To comment #4:

I'm fairly sure he means action adventure combat game--of which those you mentioned are not. That's why he mentions DMC and Ninja Gaiden.

Anonymous said...

why would someone bring up crash and gta when this blog post is about a combat game? my goodness.

i agree with the author's statement about japanese recognizing an american combat action adventure game. no other american combat game has even come close to getting the japanese responsiveness down...not even close.

Chrillo the Magnificent said...

Eric, did you see this other blog that talks about logic/rules for fighting games:

http://www.djamesgoddard.com/

Also, dude, you need to update your email addy on LinkedIn. We can't keep meeting like this!

eric williams said...

To Margalis:

I am not sure where you get your time esitmations from with regards to the L1 specials moves but I can assure you that you are way off. All of the specials are less than 2.5 seconds! Just wanted to clear that up...

To Chrillo the Magnificent:

Hey sorry for not updating my LinkedIn, it is has been updated... thanks for stopping by the blog!

Also I met Goddard once a long time ago but I doubt he remembers me. All of the Street Fighter community kinda goes way back, I know Derek talks to Goddard still... then there is Sirlin and a few others in the game biz from that group. Anyhow I will try to post more stuff like this when I get the chance.

Anonymous said...

Great post...it was almost like I was sitting with you, Derek and Omar at Lucky Dog! :P Damn I want some cheese fries...

-John

Joseph said...

Excellent read!

Anonymous said...

Yeah GREAT article Eric, as always i like how you break stuff down.

- Mark "Flipmeign" A.

Anonymous said...

Yeah, great stuff. You really should do a GDC session about this stuff.

Anonymous said...

to erik......you are missing a lot about cancels in dmc.

you can't only cancel between melee and fire....you can also:

-cancel almost every slash into another move....like you can cancel each ground combos slash into a streak/stinger, into an high time/high roller....into a shuffle....in air you can cancel each slash into helm breaker/split...or into calibur....etc etc.
also don't forget about Devil Bringer moves with Nero on DMC4.
almost every melee attack can be cancelled into another melee attack

-block cancels: cancels done using royal guard's block feature.....like 2 ground slashes, block, 2 ground slashes, block etc....in pro-users hands, you can't see the block animation.

-for dante: devil arms switching cancels......you can cancel each attack into an attack of another devil arm, switching them on-the-fly.....like doing 2 rebellion ground slashes, then switch to agni&rudra and continue with a&r combos.

-jump cancels: the ability to cancel EACH aerial move into the same repeated move or another move, using the feature about jumping on the body of the enemy.
for example you can launch an enemy in air, perform a move (like cerberus' Swing), then fast push jump button and then you can repeat Swing (or another aerial move)......with the correct timing, you can do swing,swing,swing,swing,swing etc in air.....that wouldn't be possible without jump cancels.
watch a dmc3 combo video on youtube....you will see a lot of jump cancels.

it's obvious that dmc series is the best about cancels :)

however imho the real problems of god of war battle system are:

-bad air combat....you can't really juggle enemies in air effectivly like in dmc.....aerial combos don't work effectivily and then to interrupt aerial game.....also aerial L1+button combos don't work effectivily

-few ground combos......you have virtually only 1 ground combo with slightly variations....
the basic combo is [][][][][].....you can variate it with [][]/\ (slam) or with [][][][]/\ that is the same slam but it's more powerful and has a rallenty jump animation.
or you can do /\/\/\ that is slightly the same thing.
so you are virtually doing the same combo ever and ever....
.....isn't the time for God of War 3 to have more ground combos that are really different between them?
watch dmc or ninja gaiden....there are many ground combos....each one with different animation....in gow they are the same combo with a slightly different attack at the end.

-secondary weapons are too secondary! blades of chaos/athena are: powerful,fast,with long reach (and some crowd controlling moves like L1+[]) and many moves....the best in a single weapon...ok that blades of chaos/athena are kratos' trademark.....but damn...other weapons aren't comparable, expecially about lack of moves!

-blade of arthemis is slow,with short range and few moves

-blade of olympus is better but lacks moves! you repeat the same combo ever and ever!

-barbarian hammer is slow, with lame combos, few combos and you can't dodge :|

-spear of destiny....the best of secondary weapons....fast, nice reach, nice combos...
the problem is that it lacks moves, like every secondary weapon!

i repeat: ok blades are kratos' trademark....but make secondary weapons better, expecially with more combos/moves! it's useless to use them if blades are better in everything (and don't talk me about using spear of destiny for Clotho's path in the end of gow2 to place bombs...it's unfair)

in ninja gaiden and dmc, each weapon is good...and you can freely choose them.....so there isn't a primary weapon and secondary weapons....there are many good weapons at your choice


-imho it would be cool to improve the blades of chaos grab feature.....i mean...when you are on the ground, you can grab an aerial enemy using blades.....well...imho if you improve this, on O button, in a similar way to Nero's Devil Bringer (dmc4) it would add a lot in gow combat system.
simply replace useless L1+O moves (very useless) with L1+O grappling feature.....so you can grab with blades the locked-on enemy......even in air...
like ground-ground, ground-air, air-air, air-ground.
it would improve a lot the battle system, allowing you to create long combos like for Nero in dmc4......isn't too strange imho.....simply make the ground-air blades grapling feature also avaible for ground-ground,air-air,ground-air on locked-on enemy

imho if you will fix:

-aerial combat
-add new ground combos for blades of chaos/athena
-improve secondary weapons, expecially giving them more combos and make them as alternate weapons and not really secondary "useless" weapons
-maybe add this L1+O blades grappling feature

gow3 combat system could easily be very deep and funnier!

waiting for your answer :D
tnx for attention :D

eric williams said...

To the last poster,

I think you sort of missed the point of my article. While everything you say about DMC is true, all you have said still fall under the group of post hit frame cancels. It does not matter what you can do but when you can do it.

As for the ground chains in GoW not having extra moves. Well we never focus on things the general user will not be using. Most players do not want to remember where a special ender comes from so that is why all the final triangles are the same with the exception of the big leaping one.

For the weapons, we design the chains to be the best because most players will stick with them. The other weapons are for fun and variety if that did not sit well with you then I appologize but that is the way we designed them.

The air combat is not meant to be as deep as the other games because most players focus on the ground combat.

I hope you are sensing a pattern by now, we cater to the average player... work should not be spent on things that most players will not engage. GoW is not just about combat like the other games so of course they are going to have so called better and deeper combat systems.

All that being said I think you should understand we design for our audience and most of the core players of the other two series are not our a big part of our audience.

Finally we played around with the chain throwing the creatures around but ran out of time and memory... the PS2 could only handle so much. Sadly I no longer work at Sony so I am unable to address the ideas and comments about how to fix the errors in game of the year 2005 and game of the year nominee 2007... sorry about that.

Thanks for the comments!

ThaYoost said...

Great read...

tnx Eric

Enrico said...

This article is damn interesting!

Thanks Eric :D

I will do my best to make World Never End combat system make honor to this suggestions.

Enrico Bottani