Real Bout changes the play controls from the previous Fatal Fury games, reducing the number of attack buttons from four to three: a standard Punch and Kick button, a "Strong Attack" button which can be either a stronger punch or kick attack, depending on the character. The game retains the three-plane "oversway" system from Fatal Fury 3, which features a main lane for fighting, with foreground and background planes used to avoid attacks or leap towards the opponent. A dedicated button is now used to make an "oversway" (or change plane) towards the background or foreground.
Real Bout introduces a Power Gauge, which fills up as the player performs normal or special techniques against their opponent or defend themselves, similar to many super move gauges featured in other fighting games. The Power Gauge allows players to perform one of three types of Special Techniques, depending of the level of the Power Gauge.
When the gauge is at least half-full and colored yellow, the player can perform "Guard Cancels", which are special counterattacks that can be performed by the player after blocking an opponent's attack. They do not consume any filled portion of the Power Gauge.
When the Power Gauge reaches MAX level while the player still has more than half of their life gauge remaining, then the Power Gauge will enter "S. Power" level. The energy in the Power Gauge will begin to deplete gradually and during that time, the player can perform "Guard Cancels" or a "Super Special Move" (a powerful Special Move). However, once a Super Special Move is performed, the remaining energy in the Power Gauge will be consumed and the Power Gauge will return to its initial state.
When the Power Gauge reaches MAX level while the player has less than half of their life gauge remaining (when the life gauge is flashing red), the Power Gauge will enter "P. Power" level. In this state, the Power Gauge will gradually drain, but the player can perform both Guard Cancels and Super Specials indefinitely until the gauge runs out. The player can also perform a "Hidden Ability", an even more powerful Special Move (similar to the Hidden Abilities in the previous game), which will consume the remaining Power Gauge at this state.
Real Bout also introduces stages with ring-outs, a gameplay feature previously introduced in 3D fighting games such as Virtua Fighter. If the player performs certain attacks on their opponent while next to the boundaries, the character will eventually destroy the barrier keeping the opponent in the ring and be able to knock them out of the stage for an easy win.
The game retains the character roster from Fatal Fury 3, with the boss characters (Ryuji Yamazaki, Jin Chonrei and Jin Chonshu) now part of the regular cast. Duck King, Billy Kane and Kim Kaphwan, who were all last featured in Fatal Fury Special, are added to the cast. Series antagonistGeese Howard reprises his role from the original Fatal Fury as the game's final boss. Real Bout was Geese Howard's final appearance in the Fatal Fury storyline, as the game's ending with Terry or Andy depicts the character's demise at the hands of either brother by falling off the roof of his tower. This was reflected by SNK's tagline for the game, "So long, Geese!" (さらば、ギース,Saraba, Gīsu?).