Game Systems

This guide section, and it's subpages, describe the Game Systems in Skullgirls. Knowing the details may give new Skullgirls players an understanding of how to improve their gameplay. Players with experience from other fighting games may want to understand the similarities and differences between Skullgirls and the mechanics of other fighters.

Glossary: An index of move properties and a general fighting game vocabulary reference.

Fundamental Systems

Frame Rate, Timing, and Animation: Frames, Frame Skip, Start Up, Active, and Recovery Frames, Block Stun, Hit Stun
Character States: Normal State, Dashing, Attacking, Hit Stun, Ground Recovery, Block Stun, Scripted Animation, Cinematic
Hit Boxes: Attack Boxes, Hurt Boxes, Physical Extent
Commands and Inputs: Fill in the list of subjects

Character Ability Systems

Movement: Walking, Dash and Run, Jumping, Air Dashes
Basic Attacks: Normal Moves, Command Normals, Normal Throws, Special Moves
Basic Defense: Blocking, Pushblock, Ground Recovery, Throw Tech
Advanced Attacks: Blockbusters, Ensembles, Tag Out, Tag In, Outtakes, Stunt Doubles, Blockbuster Sequels
Combo Mechanics: Notation, Chains, Cancels, Links, OTGs, Landers, Character Size and Weight

Unblockable Protection

Defending characters get a brief period of unblockable protection after successfully blocking any attack that forces a specific block direction. This protection lasts for the duration of the attack's hit stop, lasting between 4 and 12f for most attacks. During this brief period all attacks requiring a change of block direction will get blocked automatically. The fearsome left/right and {{#motion:high / low}} unblockable setups, common to many 2D fighters, will not guarantee a successful hit as long as the defending player can block the first hit. At worst, these tactics will require the defending player to make a 50/50 guess.

File:SG unblockable.png

Cerebella guards high against Painwheel's j.MK, then automatically blocks Ms. Fourtune's c.HK custom Ensemble.

The Infinite Prevention System

Hitting an opponent with an infinite combo allows the defending player to break out of the combo with a unique Infinity Breaker attack. An infinite combo uses a repeated sequence of the same attacks and can deal 100% damage to the defending character. When the Infinite Prevention System (IPS) detects an infinite combo, hit sound effects and impact effects change and any attack input by the defending player will execute the Infinity Breaker.

Infinity Breaker

All characters have identical properties for their Infinity Breaker: 10f of invincible start up, 23f active frames, and 28f of recovery. The Infinity Breaker can start the frame after an IPS triggering attack lands. On hit, the Infinity Breaker deals no damage but will scale damage to 50% if it starts a combo. The defending character is invincible during the the entire Infinity Breaker and can take any available action at the end of recovery frames as long as the Infinity Breaker hits or is blocked. If the defending player preforms an Infinity Breaker immediately after a projectile hit, the Infinity Breaker always has this full invulnerability even if it misses the opponent. Under normal circumstances, both characters will recover on the same frame after a blocked Infinity Breaker. If an Infinity Breaker is triggered from a non-projectile attack and does not hit the opponent at all, the recovery frames are vulnerable and there is an additional period of recovery as the character falls slowly to the ground and lands standing.

Infinite Detection

I'm not sure why people think this IPS is complicated [...] the rules are still simple to explain - "don't start a chain with something you already hit with, and your combo is always legit." You get 2 free sections before moves are even counted toward this limit (your first and second chains) and one more free section where moves are kept track of but the limit isn't enforced yet (the entirety of your jump if you're in the air, or your next chain if you aren't). That's it. You can determine exactly whether or not a combo is possible just by writing it out: "Did I already use s.LP? OK, can't start another chain with that." And if something doesn't work, the hitsparks change color and you immediately know which move caused it. You also immediately know why, because the ONLY THING that would cause it is you having used that move before. [1]

"Don't start a chain with something you've already hit with" is the only rule. The exception is your first jumpin sequence, first ground chain and first air combo. [2]

- Mike_Z

Combo Sections and Stages

IPS reads combos in smaller sections, chains, or loops as they happen. It offers the most freedom to the attacking team during the first sections. As the combo continues, the combo stage increases. A higher combo stage represents increasing restrictions on a combo as it becomes closer to an infinite. Any attack can start a new section, which will continue through any chain combo of normals, a cancel into a special move, or a cancel into a Blockbuster. Leaving the ground with a jump, landing on the ground, air dash canceling, and preforming a link in a combo all start a new section for the combo and increase the combo stage.

The Practice Room's combo stage counter shows the player exactly when IPS increases the restrictions for the combo by counting up from 0 to 5. The IPS effectively ignores the combo for the first free sections, remembering all attacks used in a combo starting with the first watched section. After a combo reaches the maximum combo stage, the IPS continues to watch and remember every attack and can trigger for an Infinity Breaker. Starting any additional section with a move that was previously used in a watched section will trigger IPS.

Order of combo stages:
- 1: Free: Optional section for a chain of jump-in attacks; cancelling to an air dash will end the chain and start Stage 2.
- 2: Free: The next chain, usually the first ground section.
- 3: Watched: The next chain.
- 4: Watched: Optional section, allowing one additional chain before Stage 5 if using an air dash cancel.
- 5: Limited: Maximum stage, same as watched and can trigger an Infinity Breaker.

Additional Rules

All standing, crouching, and command normals from the same button count as the same attack to IPS. Once one version of the normal gets watched, all versions are watched. IPS considers air normals separate attacks but are similarly tied to any air command normals on the same button.
Different button strengths of same special move count as the same attack to IPS; once one strength of the special attack gets watched, all of them are watched. Similar to normal attacks, IPS watches the air version of specials separately and considers all strengths as one move.
Blockbuster are never watched and can't trigger IPS. Infinity Breakers can be preformed while getting hit by a Blockbuster if something else triggered IPS first.
Ensembles count as their own section. IPS will watch Ensemble attacks and remember them if the Ensemble character becomes the point character before the end of the same combo.
A {{#motion:throw}}, if used in a combo after a {{#motion:stagger}} or {{#motion:crumple}} stun, counts as its own section. Starting a combo with a throw will start the combo at Stage 2. Throws and attacks cannot trigger IPS. Infinity Breakers can never be preformed during a throw's scripted animation.
Watched attacks will carry over to a teammate if the teammate takes point after a standard Tag In, but not after a Blockbuster Sequel.

Character-Specific Rules

Cerebella's {{#motion:rpdfire}} j.LP will infinitely chain into itself but can only trigger IPS on its first hit.
Parasoul's j.MK and (air) ↓ + MK can chain into any of her other air normals. Chaining "down" will start a new combo section.
The direct hit from Parasoul's Napalm Shot will get watched like any other special move. IPS ignores the exploding tears from this attack.
The explosion from Parasoul's Napalm Toss will get watched like any other special move. Although placing the tear does not cause a direct hit, chaining into the special move means the tear will not trigger IPS when it eventually does explode.
IPS completely ignores Ms. Fortune's head. Hit from the head can never trigger IPS, the head's attacks are never watched, and it can't start a new section or increase the combo stage for the body.
Painwheel's Flight is considered the same as an air dash cancel to IPS and can be used to get a Stage 4 chain.

Drama

The Drama (or undizzy) gauge compliments the IPS system and can trigger an Infinity Breaker based on a parallel set of rules. Once a combo reaches Stage 5, additional hits fill the opponent's unseen Drama gauge. Once the gauge fills to 350 total drama, starting a new chain will begin to show a green version of the IPS hit effect and allow the opponent to execute an Infinity Breaker. Attacks add Drama based on set values for the type of move: light normals add 15 Drama, medium normals add 20, heavy normals add 30, and specials add 20. Attacks with multiple hits will add their Drama on the first hit only. Supers do not add to or activate Drama. Drama decays over time when the opponent is not in hit or block stun, with a full Drama gauge of 350 taking 60f. A successful ground recovery immediately clears Drama.

IPS Examples: Analysis of combo videos showing IPS mechanics in older patches. These examples may also explain why Drama was added to Skullgirls with 1.02.