Sega All-Stars Duel

Sega All-Stars Duel is a 2024 crossover tag fighting game developed by Sega AM2 and published by Sega. It is the 5th game in the Sega All-Stars series, following Sonic & All-Stars Racing: Transformed and the latest installment since 2012. It is the second crossover fighter from Sega and first with tag mechanics featuring a much more diverse cast from Fighters Megamix on the Sega Saturn with modern and retro Sega characters. It also features a unique Chaos System featuring the Chaos Emeralds from the Sonic the Hedgehog series, giving unique abilities exclusive to each character. It was released on July 16, 2024 for PlayStation 5, Xbox Series X, Nintendo Switch and Microsoft Windows.

Plot
Dr. Eggman, seeking ultimate world domination, steals one of the Chaos Emeralds (the blue Chaos Emerald) and tries to merge it with the Phantom Ruby, creating the ultimate power source. However, in doing so, he creates a Genesis Wave that splits many realities and universes into one. In the process, Magatsu steals the Master Emerald and is on a multiversal destruction course. Characters from many conjoined Sega franchises must unite in a race and battle against time with the help of the Chaos Emeralds.

Gameplay
Sega All-Stars Duel is a tag fighting game in which two sets of characters fight alongside each other. It allows side stepping around the stage while in a confined 3D fighting plane similar to Virtua Fighter. It also features a Free-For-All meter, located in between both health bars and filled by combos from both characters. Upon activation by either character, the game enters a free movement phase and both duos can move freely around the arena similar to Power Stone and attack simultaneously for a limited time. A character can also activate it while being attacked in order to break combos. While in Free-For-All mode, the player can change point characters, maximizing damage output. During this time, for select character duos, both characters can perform specific cinematic tag combos in unison with each other, albeit at the cost of Chaos Meter. Select duos, such as members of Team Sonic can perform individual assists without draining Chaos Meter. In the game's online 3-v-3 tag modes, the third character can be used for assists while in Free-For-All Mode.

The game also features a Chaos Meter, filled individually by character combos. Once activated, the point character summons the Chaos Emeralds, granting them a unique ability for a limited time, such as hammer throws for Amy Rose. It also buffs that character's best attribute, such as faster combos for Jacky Bryant, bigger hit stun and damage output for Akira or rapid fire for Rage/Smarty. While in Chaos Mode, players can unleash a Hyper Combo which can be used in conjunction with the other abilities while in Chaos Mode. However, doing so will end that character's Chaos Mode. Sonic, Knuckles and Shadow, while in Super mode can instead opt to transform into their Hyper forms for further damage, durability and speed buffs and special abilities (such as Hyper Flash, tremors and multi-directional Chaos Spears, respectively).

Stage effects are also present in the game. Characters/enemies from that stage’s respective franchise may appear in the background, occasionally attacking either in the background at random intervals or from the end(s) of the stage in the form of assists. Certain cinematic stage effects can also be triggered in the form of counters while in Chaos Mode via Chaos Control (dubbed Chaos Counter), such as wall breaks, assists and environment changes.

Game Modes

 * Arcade: Play a series of bouts against random teams before facing the sub boss and end boss.
 * Versus: Play individual matches in a single or multiplayer environment.
 * Survival of the Dead: fight swarms of increasingly-resilient zombies in teams of 4 with randomly-appearing power-ups before facing Magician outside the Curien Mansion in a Dynasty Warriors-like action mode.
 * Online: Play in online matches against random players.
 * Training: Practice with a chosen character.
 * Trial: Perform a series of missions performing all the different moves in a character's moveset.
 * Theater: Watch saved replays or character endings.
 * Options: change sound, difficulty and control settings.

Characters
Sega All-Stars Duel's base roster features a total of 40 characters. An additional 10 characters were later announced as DLC, bringing the total roster to 50 characters. Michael "Rage" Hardy and James "Smarty" Cools are pallet swaps and selectable from the same character slot with the other used for assists. Both have attribute differences with the same moveset, the former having faster weapon draw and the latter having more critical hit damage as an extension of his better gun accuracy.