Here’s a translation of Sakurai’s two-part column on hitstop/hitlag as it appears in Smash. Enjoy!
This translation is for fan use only, and may not accurately reflect Masahiro Sakurai. If you enjoyed this article, I would strongly encourage you to support Sakurai by buying his books, and support Famitsu by buying their magazine. If you have any questions about this article, please contact the administrator.
Thinking About Hitstop
Think About the Video Games, Weekly Famitsu Vol. 490-491
As a game designer myself, I’d like to use this column to talk about game design every so often. For this entry, I want to focus on hitstop.1
“Hitstop” is a term used to describe a technique employed primarily in fighting games. When you strike the opponent, both parties momentarily freeze, emphasizing the power of impact. It’s a crucial effect.
Hitstop features most prominently in 2D fighters. Every time you land an attack in games like Street Fighter and Guilty Gear, the characters appear to stop in place. In games like Tekken and Virtua Fighter, however, you don’t see much hitstop. Perhaps it isn’t very compatible with 3D fighters.
Games in the Dynasty Warriors series don’t employ much hitstop, either, probably because you attack large groups of enemies at once. If the action stopped every single time you landed an attack, you would likely end up frozen for a long time, reducing the overall game speed. Conversely, when you get bit by a Shellcreeper in the original Mario Bros., you and the enemy both freeze, and Mario falls off the screen. This sort of effect could also be considered hitstop in a broader sense of the word.
I employ a lot of hitstop in Super Smash Bros., and I’d like to take this opportunity to introduce the concept. By explaining how I use hitstop to spice up the action, I hope to help you all understand the finer details of this mechanic.
・Same Amount of Time
With hitstop, both you and your opponent freeze for the exact same amount of time. In general, the more damage an attack inflicts, the longer the hitstop period. Some attacks also include a slo-mo effect, but that is a separate concept.
・Intentional Time Change
In Smash, the hitstop period is determined not only by the amount of damage, but by certain factors exclusive to each individual attack. For example, the tip of Marth’s sword is stronger than the rest of the blade. I emphasized this difference by adding an increased hitstop modifier at the tip, and reducing the hitstop created when slashing with the edge of the blade. Likewise, Ryu recently joined the fray as a DLC Fighter, and in order to recreate the character of the original game, I greatly increased the hitstop on his attacks. Even then, he still has less hitstop in Smash than he did in Street Fighter II!
・Adjusting for Free-for-Alls
Ideally, I would love to extend the hitstop period in Smash just a little more, but I refrain. Why? Because of free-for-alls. When you and the opponent are frozen in hitstop, that creates a chance for a third player to move in and strike. This is never an issue for one-on-one fighting games.
Projectiles have comparatively less hitstop than other attacks, whereas attacks with electric properties automatically have an increased hitstop modifier. In addition, I’ve implemented a cap on the maximum amount of time characters can be in freeze frames. Regardless of how much damage an attack inflicts, the hitstop period will never exceed this limit. This is important, given absurdly powerful weapons like the Hammer and attacks like Final Smashes.
Changing the subject for a moment, I’ve noticed characters vibrate slightly when they get hit in 2D fighters and games using sprites. This simulates a sense of shock more than having the characters freeze.
However, you don’t see much vibration in 3D fighters. The damage vibrations you see during hitstop frames are difficult to implement in 3D fighting games. Here are some of the unique ways we’ve implemented this into Smash.
・Making the Attacker Move, Too
Normally, only the character that takes damage vibrates, but in Smash, the attacker also vibrates slightly.
・Keeping Hurtboxes Stationary
If the body vibrated normally, that character’s hurtboxes would also move slightly, causing attacks that should have hit to miss and creating inconsistencies. In Smash, we solve this problem by having the characters vibrate visually, but keep the hurtbox locations static.
・Grounded = Horizontal, Aerial = Vertical
In Smash, grounded characters in hitstop vibrate side to side and aerial characters in hitstop vibrate up and down. When you consider the fact that characters face each other side-to-side, having them vibrate vertically is better, but a grounded character’s feet would clip into the stage. It’s a concern that didn’t exist in 2D games.
・Adjusting Amplitude to Camera Distance
In games where the camera pans in and out over far distances, it may become difficult to see the character vibrate from far away. Thus, we alter the intensity of the vibration depending on the distance of the camera. When the camera is far away, the characters are actually vibrating quite a lot, but you might not be able to tell so easily.
・Slowly Focusing the Vibration
The distance that characters vibrate is not set, starting out large and growing much smaller by the end. By calculating the freeze frames beforehand and dividing, we can appropriately decrease the intensity of the vibrations.
・Making Damage Look Painful
With 2D games you can draw the animation frame by frame, so the second a character is hit, you can instantly make them look like they are in a lot of pain. When doing this with polygons, you’re frozen the instant you take damage, and it can look quite ambiguous. In Smash, after the first frame of the flinch animation, the character enters a painful-looking hurt animation. However, switching from one to the next so quickly would look strange, so during hitstop, we take four frames to smoothly transition from the initial flinch to the hurt animation.
Finally, it’s complete. I think this is a particularly unique mechanic.
・Moving Slightly During Hitstop
If you look closely at a powerful attack by a swordsman, for example, you’ll see the sword actually moves very slowly. During hitstop, the attacking character moves at such a miniscule speed that you wouldn’t be able to notice the difference in one frame. When hitstop is over, the character’s movement returns to its initial integer value, and the game proceeds as if nothing had changed. It’s a trick similar to slow motion—a hidden flavor.
We can also individually remove this movement for attacks like Mario’s Up Special, where the effect might make things feel off.
Simply put, even for freeze frames where it appears as if you and your opponent are just frozen in place, it’s not that easy. If you break it down, there are a lot of little improvements that we’ve made, and as a result it makes the impact feel a little bit stronger with each addition. You could Smash is still a work in progress.
These improvements are not suggestions made by the staff; everything is proposed and designed by the director. We don’t have the time for trial and error, so we have to nail it on the first try, and don’t make a lot of changes.
To avoid long periods of trial and error, looking to other games is crucial. There is more than enough to teach and inspire us.
1 Smashers refer to this as “hitlag,” but since “hitstop” is the exact word he uses, we’re going with that.
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