The red area of Zangief's attacks refer to the offensive hitting areas of his strike hitbox that result in an action if it makes contact with a hurtbox.
A hitbox is a term used in fighting games that refers to the attacking area of an offensive action.
Description[]
The hitbox (marked in red) is the area hits the opponent if they touch it.
Hitbox refers to the area that an attack has that is meant to do contact with the opponent's hurtbox. When it makes contact with the hurtbox the attack can either hit or be blocked.
Priority[]
Priority works differently in Street Fighter than other games as it doesn't have mechanics such as the "Port Priority" system the Super Smash Bros. series has. Priority can mean different definitions. Generally when speaking of strikes, the general meaning refers to the startup frame data, hurtbox extension of the attack, and the reach of the attack. Anti Air attacks tend to give very little vertical hurtbox extension for example. This is to ensure that they can work to task. It should be noted that when not taking invincibility into account, low priority attacks such as Rufus's 16 frame startup can beat Cammy's 3-frame jab with the right timing.
Street Fighter V introduced a true priority system. Within this system (assuming both attacks active hitbox activate at the same frame) a medium will defeat a light attack, and a hard attack will defeat a medium. Attacks of lesser strength CAN still catch the startup of harder attacks. Interestingly, some command grabs from characters like Rainbow Mika have an odd mechanic that if two players use the same grab the winner is literally determined by if the game is in an odd or even frame.
Invincibility[]
Invincibility refers to the amount of frames during which a character lacks any "vulnerable" hitboxes/hurtboxes (e.g. the aforementioned Shoryuken), meaning that they cannot be hit.
This is often done in one of two ways depending on the game; hitbox/hurtbox invincibility often refers to hurtboxes either shrinking and/or disappearing in order to completely phase through attacks. Attribute invincibility is when while the hurtbox is still registered, it becomes invincible to specific types of moves within a certain frame without radically shaping itself and/or disappearing (e.g. a move that is completely invulnerable to lows or highs despite their hitboxes contacting the hurtbox during its period of attribute invincibility). An example of specific hitbox invincibility can be seen with Ibuki's EX Neck Breaker in USFIV where it is completely projectile immune but still loses to grabs and strikes or Rose's EX Soul Spiral that is completely immune to strikes and projectiles she can be thrown out of the attack.
Types of hitboxes[]
Street Fighter in general tends to use three types of hitboxes. Strike, Projectile, and Throw (grab).
Strike[]
Most strike hitboxes tend to use the same hit and blocked effect. (Hit effect shown here.)
Arguably the most common hitbox. Most normal, unique, and a good amount of special attacks tend to be of this hitbox type. Strike hitboxes are used for a multitude of reasons, either single hit attacks, Combo's, or projectile bypass. Every character has access to this type of attack. Interestingly, some thrown items such as Ibuki's Kunai and Rolento's Stinger are classified as strikes rather than projectiles. This comes with the benefit of these attacks being able to stop projectile immune actions but at the price of being able to be knocked away when they themselves make contact with other non grab hitboxes.
Types of strike hitboxes.[]
High[]
Most jumping attacks use a high hitting hitbox, meaning that a crouching block can not stop this kind of attack and it has to be blocked standing.
High hitting hitboxes refer to attacks that can not be blocked low. Every character in the game has access to this style of hitbox in the form of aerial attacks. Some characters have aerial target combos such as Ibuki's Target Combo 1 that despite using 2 hits in the air, the second can be blocked low, or others such as Chun-Li has a double hitting hard punch aerial attack that the whole sequence has to be blocked high. Most special and unique attacks such as Cannon Spike and Falcon Kick can actually be blocked low despite being aerial attacks. Some special attacks such as Hien can only be blocked high, despite starting from the ground.
Overheads (such as Hammer Kick shown here) can not be blocked low, similarly to jumping attacks these attacks can not be blocked crouching. Their regular usage is to break through defenses.
Overheads[]
A subcategory of high attacks, overheads serve as a grounded option that lack the telegraphed nature of a jumping animation, letting them serve as an option against crouch-blocking opponents.
Overheads vary in usage, with attacks such as Collarbone Breaker or Flower Kick being mixup options used to close out a round, while others such as Kobekudaki or Divine Retribution can be converted into further combos. Characters that do not have access to overheads tend to either have very far reaching Command Grabs or Walk Speed to help them close distances.
Low[]
Most crouching attacks that involve kicks tend to be only blockable while holding down-back.
In contrast to high attacks, low attacks cannot be blocked while standing. For nearly every character in the series, crouching kick attacks hit low, with the Crouching Heavy Kick serving as a sweep. Low confirms are a powerful tool in a characters moveset, as their speed, range, and combo potential allow for conversions from a safe mixup. Long reaching low attacks such as a Crouching Medium Kick are especially coveted due to their utility in neutral against walking opponents, and are often special-cancellable. Because of these strengths, certain attacks are designed as 'low crushes', moves built to avoid low hitboxes and punish the opponent, such as Bonshogeri.
While not common, some characters (especially in cross over games) have standing attacks that still hit low. A notable example would be Asuka Kazama's forward MK in Street Fighter X Tekken. These can bypass some rules for lows, such as standing low attacks bypassing the immunity Launchers have for typical crouching low attacks.
Projectile[]
Unlike strikes, not every character has access to projectile hitboxes. Projectiles usually are fireball style attacks that are shot, separating the hitbox from the user's hurtbox. The Hadouken and Tiger Shot were the first of this type, as they both debuted in the original Street Fighter.
Projectiles can vary in strength, using the number of hits to determine which projectile continues in traveling when two collide. EX projectiles often have two "points" and go through 1 point projectiles after they lose one hit point themselves, resulting in a single hit fireball. Super Combo Projectiles
Projectile invincibility is a common form of invincibility in attacks, punishing predictable tactics often with a forward advancing attack. As most projectiles travel above the ground, characters can also Low Profile and avoid the move by shrinking their hurtbox accordingly.
Not all attacks with projectile hitboxes travel. Kiko Kai, Tenrai, and Kobokushi use disjointed projectile hitboxes that interact with other projectiles accordingly while remaining stationary. Certain attacks are also designed to nullify projectiles specifically while not necessarily being projectiles themselves, such as Abi Blaster or Flash Chop. These attacks abide by similar projectile durability rules, being able to nullify single hits but being weak to multi-hit projectiles.
Despite not actually being shot, some hitboxes such as Ibuki's Tenrai are still projectile. The presence of KI is an indicator of a projectile hitbox.
Grab[]
All grabs and command grabs use the same style of hitbox called "Grab"
Grab hitboxes bypass blocking and are available to all characters in the form of standard Grabs and Throws. Grabs generally cannot be used on an opponent in hitstun or blockstun, though they are capable of beating Super Armor. During a throw animation, both characters are invincible to any other forms of hitboxes, letting certain mixups and scenarios be avoided if a player starts a throw at the proper time. Command Grabs are a variant of grabs that require an input in exchange for larger ranges, more damage, or better advantage on recovery.
Ibuki using her air throw Tobizaru against Ling Xiaoyu in Street Fighter X Tekken.
Most throws do not work against airborne opponents, with some attacks such as Mallet Smash being considered airborne in spite of being performed on the ground specifically to serve as an option against throws. In certain cases however, Air Throws can be used against airborne opponents in exchange for not being usable on grounded ones.
Unique properties[]
Some attacks do not follow the standard rules of hitboxes and can have a mixture of attributes of each attack type
Stun Gun Headbutt[]
Atypical for a command grab, Stun Gun Headbutt is capable of grabbing both air and grounded opponents after Alex starts descending. In exchange for this however, Alex is vulnerable to being hit out of the initial attack.
Hitgrabs[]
Certain attacks combine aspects of a command grab and a strike. Two primary examples are Oro's Niou Riki and Ibuki's Raida. On contact with an opponent's hurtbox, the subsequent follow-up appears as a 'grab', and depending on the game, gains certain aspects associated with a command grab, such as the Street Fighter V Raida not being able to be back rolled. This also allows Raida to catch airborne attacks and extended ungrounded hurtboxes like Dhalsim's extended limb attacks.
Ibuki's Raida might seem like a command grab, and it has the whiff recovery of a command grab, but it is actually a strike hitbox.
Meido Gohado[]
Unlike every other Ultra Combo projectile Meido Gohado uses a strike hitbox in conjunction with the projectile in order to check distance. The hitbox projectile is used to check if it was a point blank hit and if it connects Oni's animation cinematic will play instead. If it doesn't connect Oni proceeds to use his ultra like any other projectile such as Metsu Hadoken. This means that attacks such as Neck Breaker that beats every projectile has to be used at a specific distance because at point blank the ultra will still hit.
Ibuki's Kunai and Rolento's Stinger[]
In this example, Zangief is seen knocking away Ibuki's Kunai with his strike hitbox jab.
As mentioned before these throwable weapons are actually classified as strikes rather than projectiles. They do not lose to projectile immune attacks but actually have a hurtbox of their own and if they come in contact with a hitbox (aside from grab) the weapon will be knocked away, similarly to when two projectiles clash with each other.
In Street Fighter X Tekken despite these being airborne objects they bypass the jump in immune check of characters like Law's anti air.
Abigail's Diagonal Jumping Hard Kick.[]
Abigail's jumping hard kick, despite being classified as a high strike attack (meaning it bypasses crouching guard) actually doesn't hit crouching characters.
Projectile Unique Attacks[]
Some Unique Attacks such as Rufus's Fragrance Palm is actually classified as a projectile in some appearances and nullifies other projectiles on contact of both hitboxes. Two projectile physical hitboxes clashing gives the same effects and follows the same "hitpoint" style of thrown projectiles when they make contact.
Ibuki's Agemen (SFXT)[]
In Street Fighter X Tekken Ibuki's Agemen made her upper body invincible. Meaning no kind of hitbox could hit her waist up. This is often confused but is different to the jump in immune property of characters like Law and Asuka with their own anti air, that only makes them invincible to airborne hitboxes rather than all kinds of attacks. This can make Ibuki avoid some attacks such as Marduk's spinning backfist or high Tiger Shots with Agemen.
Gouken's Amaroishi[]
Gouken using Amaroishi in Street Fighter IV.
While some Command Grabs such as Hugo's Ultra Throw or Abigail's Abigail Smash can be comboed out of. Gouken's back throw Amaroishi is the only regular throw (without enhancements) that can be fully comboed out of. The most popular option is Shin Shoryuken (when available).