Gameplay Overview
Advanced Mode
Block - Hold back - While blocking, you take no damage from normals and a single pixel-per-hit when blocking special/desperation moves. You can also block in the air while jumping up or back. Ground normals cannot be air guarded.
Backdash - Tap back twice quickly. During a backdash, you can perform air command normals and air special moves. Using a command normal will cause the trajectory of the backdash to change.
Run - Tap forward twice quickly. Hold the second tap to keep running. In KOF98, when you simply tap f,f to run, you will run a certain distance before you stop. This can be canceled by jumping, crouching, or attacking, but not by blocking. You can use this period to buffer moves such as command throws. For example with Ralf or Clark, you can tap f,f, then do the hcf motion for their command grab while you are moving forward, without having to keep holding forward over that first couple character spaces.
Also, there is a small recovery when you release f to stop a run. When running in to attack, keep holding forward if you're going to do a standing attack, or move to d/f for a crouching attack. This makes attacking from a run seamless. You can also hold d/f to keep charge a charge-down special move while running.
Roll forward - Press A and B simultaneously. Rolls are invulnerable from the very start, and vulnerable at the end. You can be thrown out of rolls as well. Since they are invincible at startup, you can use rolls as a wakeup 'reversal'. But unlike in later KOF games, you cannot mash the input. In KOF98, if you are not fully recovered from something and try to input A B, you will get a standing A attack. Using that as a reversal will get out hit on counter, so be accurate with your roll timing.
Roll backward - Press back and A and B simultaneously.
Recovery roll (tech roll) - Press A and B simultaneously as you are touching the ground from getting knocked down. Some moves/knockdowns are not rollable. You can mix this up with staying on the ground to mess with your opponents setups on wakeup.
Throw break - Press back/forward any button immediately after you are thrown. Some normal throws are not breakable, and instead you can mash all the buttons and directions to lessen the damage and get out faster.
Guard Cancel Roll (emergency roll) - Press A and B simultaneously or while guarding a move (hold back to roll backwards). This uses one power stock.
Guard Cancel Strike (CD counter) - Press C and D simultaneously while guarding a move. This uses one power stock.
MAX mode activation - Press A, B, and C simultaneously. This will use one power stock and give you a meter that shows you how much time you have left in MAX mode. While in MAX mode you get a large damage bonus (25% increase), more pushback on hit for all attacks, and any Desperation Moves (supers) performed during this time will become Super Desperation Moves, and will take one power stock in addition to the one you used to go into MAX mode. These SDMs are enhanced versions of the normal supers and will do more damage/hits, etc.
Quick SDM - Super motion with A/C or B/D. Will use three stocks to do an SDM without MAX mode.
Extra Mode
Block - Hold back - While blocking, you take no damage from normals and a single pixel-per-hit when blocking special/desperation moves. You can also block in the air while jumping up or back. Ground normals cannot be air guarded.
Backdash - Tap back twice quickly. During a backdash, you can perform air command normals and air special moves. Using a command normal will cause the trajectory of the backdash to change.
Dash - Tap forward twice for a command dash. This can no longer be canceled into aerial attacks, thus removing previous infinites. Character dash speed and distance varies greatly.
Evade - AB, will make your character invincible during a sidestep. You're stationary while evading and unable to tech throws. It's possible to evade multiple times in a row to avoid chip damage.
Counter Attack - During Evade, P / K. Can be followed up by specials or supers.
Recovery Roll - Press A and B simultaneously as you are touching the ground from getting knocked down. Some moves/knockdowns are not rollable. You can mix this up with staying on the ground to mess with your opponents setups on wakeup. Recovery rolling will also remove all initial throw invincibility on wakeup.
Throw Escape - Unlike in '98, the new Extra Mode can tech throws except when caught doing an Evade.
Guard Cancel Roll - While blocking, press f/b + AB. Uses one stock. Will only use a portion of your meter when in MAX mode. Known as a 'GCAB'.
Guard Cancel Strike - While blocking, press CD. Uses one power stock, or your entire MAX mode meter. Known as a 'GCCD'.
Charge Power Gauge - Hold down ABC (until Power Gauge is at maximum capacity).
Quick MAX - ABC while executing certain normals or specials. Will cancel some frames and enter MAX mode, and can be used to continue combos. Also can be done during air normals and specials. It requires a stock.
SDM - While life bar is flashing, enter MAX mode. Any super will now be an SDM.
Flashing Life Bar - When your life bar reaches a certain point, you will be able to do DMs for no meter. You'll have to wait about one second between supers, though. The threshold for entering this state increases for each character loss.
Power Gauge
The meter will charge automatically when you do attacks or get hit, albeit slowly. By charging the meter manually, you can build it much faster. Once charged, you get a stock, which can be used at your discretion for entering MAX mode or for a DM. Each character will transfer a stock to the next character, and the amount of life needed to enter flashing mode increases.
Ultimate Mode
Ultimate Mode is an amalgam of both Extra and Advanced modes that allows you to mix and match system direction. On the menu, you will first choose whether you want Running or Dashing, then Rolling or Evading, and finally what meter type you want: Advanced or Extra. All the top choices are Advanced, all the bottom choices are Extra.
Advantage System
When a character is defeated, the winning character regains a small amount of health. In addition, losing a team member gives the losing player an advantage.
In Advanced mode, you can have an extra stock slot after each fighter is lost. The first fighter has a maximum of 3, the second fighter has a maximum of 4, and the last fighter has a maximum of 5.
In Extra mode, your bar doesn't shorten like in old KOF '98, but your life goes into flashing red earlier for each defeated character. It's around 25% for 1st, 30% for 2nd, and 35% for 3rd. - (Dandy J)