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.
- Frame Rate, Timing, and Animation: Frames, Frame Skip, Start Up, Active Frames, Hit Stop, Hit Stun, Recovery Frames, Block 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? How many frames between each direction input, what dps taking priority over qcf, stuff like that
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
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 / 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.
|Cerebella guards high against Painwheel's j.MK, then automatically blocks Ms. Fortune's c.HK custom Ensemble.|
The standard jump start up animation gives every character 4f of against attacks. Stopping any ground throw using these frames gives full invulnerability to the remaining frames of throw start up, then gives the defending character 8f of additional projection against anti air throws. Typical anti air throws, such as Cerebella's Excellebella and Big Band's Take the 'A' Train, are throw on hit attacks that can't be blocked while a defending character has upward momentum. The 8f of protection removes this property from anti air moves, allowing the defending character to avoid both a ground throw and an anti air throw that hit on approximately the same frame.
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.
All characters have identical properties for their Infinity Breaker: 10f of invincible start up, 23f active frames, and 28f of recovery. The defending player can press any button to input an Infinity Breaker the first vulnerable 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. Under normal circumstances, both characters will recover on the same frame after a blocked Infinity Breaker. If an Infinity Breaker 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.
If the defending player waits 90f after IPS gets triggered, the Infinity Breaker will always have a fully invulnerable recovery even if it misses the opponent. Starting an Infinity Breaker immediately after a projectile hit will also guarantee a fully safe Infinity Breaker.
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. 
"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. 
- 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.
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.
- 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 , if used in a combo after a or 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.
- Cerebella's 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.
- If Parasoul cancels the recovery of an (air) Napalm Toss to start a second air chain in the same jump, it is considered the same as an air dash cancel to IPS and can be used to get a Stage 4 chain.
- 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.
The Drama (or undizzy) gauge compliments the IPS system and can trigger an Infinity Breaker based on a parallel set of rules. If the IPS prevents abuse of short, looping combos from a single character, building Drama prevents the longer and equally abusive combos from multiple characters. Once a combo reaches Stage 3, additional hits begin to fill the opponent's unseen Drama gauge. If the combo reaches Stage 5 and the defending character has 240 or more Drama, the start of any new chain in the combo will 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: 15 Drama
- Medium normals: 20 Drama
- Heavy normals: 30 Drama
- Any special: 20 Drama
Other attacks, such as normal throws or Blockbusters, do not build Drama. Ensembles add appropriate Drama for the Ensemble's attack type. An attack that chains into itself (such as with Chain Twice) and attacks with multiple hits from a single button press will add Drama only on the first successful hit.
Drama decays over time when the opponent is not in hit or block stun, and if it accumulates over the 240 limit it will take even longer to clear. A full Drama gauge will drain over a maximum of 60f for 350+ Drama. A successful Ground Recovery immediately clears Drama.
Counter hits subtract Drama, which can put Drama on the defending character to a negative value and allow for some impressive counter hit only combos. Drama subtracts on counter hit according to the type of attack:
- Light normals: -25 Drama
- Medium normals: -50 Drama
- Heavy normals: -100 Drama
- Normal throws: -50 Drama
- Specials: -50 Drama
- Any Ensemble: -25 Drama
The Drama Gauge shows the current Drama on the defending character's HUD. Other IPS related rules have no visual indicator other than the hit effects after triggering an Infinity Breaker.