It is the sixth installment in the Mortal Kombat franchise, adding new gameplay mechanics (including a manual "Combo Breaker" system, stage-specific "death traps", and stage-specific weapons), online multiplayer, new mini-games, and a new adventure/fighting hybrid Konquest Mode that serves as the game's prologue.
The story of Mortal Kombat: Deception takes place right after Mortal Kombat: Deadly Alliance. As the deadly alliance of emperors Quan Chi and Shang Tsung emerge victorious against thunder god Raiden's warriors, a new evil (the Dragon King and former emperor of Outworld, Onaga) appears to seek six artifacts (the Kamidogu) that grant him supreme power over all realms. The game's main protagonist is Shujinko, a warrior with the power to copy the abilities of other fighters.
The Krypt and the concept of "koins" return from Mortal Kombat: Deadly Alliance, which is used to unlock characters, stages, alternate costumes, concept art, promotional material, and additional special moves for Shujinko. Some content and characters, however, can only be unlocked by accessing special areas of Konquest Mode.
The game was later released in March 1, 2005 for the GameCube and November 13, 2006 for the PlayStation Portable (under the title "Mortal Kombat: Unchained"), each with bonus characters from previous Mortal Kombat games. A bonus disc came in collector's editions of the PlayStation 2 and Xbox versions, including video biographies and a port of the original Mortal Kombat. The Puzzle Kombat part of the game was later ported to the Nintendo DS on November 12, 2007 as a bonus to the DS port of Ultimate Mortal Kombat 3.
Mortal Kombat: Deception builds upon the gameplay from Mortal Kombat: Deadly Alliance. Players have four attack buttons, a Block button (R2 on the PlayStation 2, Right Trigger on the Xbox), and a Change Fighting Style button (L1 on the PlayStation 2, Left Trigger on the Xbox). The Special Attack button is replaced with a dedicated Throw button (R1 on the PlayStation 2, Black Button on the Xbox) and players now have a Grab Weapon button (L2 on the PlayStation 2, White Button on the Xbox) for picking up stage-specific weapons.
Fighting Styles and Fatalities
Like Mortal Kombat: Deadly Alliance, players have two fighting styles based on actual fighting styles and one weapon fighting style. One character, Noob-Smoke, switches between Noob Saibot and Smoke as the two fighting styles (however, they do not have a weapon fighting style). Each character (except the characters exclusive to the PSP version) now has two Fatalities and a special new "Hara-Kiri" suicide finisher, which the losing player can perform.
Making a return from Mortal Kombat 4 is the ability to pick up and drop weapons. Certain stages have special weapons that can deal greater damage. However, these weapons must be picked up and can be dropped by switching fighting styles, getting hit, or using a special move. Stages also now have "Death Traps", which are similar to Stage Fatalities except for the fact that players can knock opponents into the traps at any time (provided they are close to the traps), immediately winning the round.
Mortal Kombat: Deception replaces the automatic "Combo Breaker" system with a manual one, similar in form to the Killer Instinct games. Players can press the Throw button while being hit with a combo to immediately break the combo. Players have a maximum of three "Combo Breakers" (as indicated by lightning icons below the life bar) per match.
In the PlayStation 2, Xbox, and PSP versions, players can play Versus Mode, Chess Kombat, and Puzzle Kombat online in 1v1 matches. This is the first Mortal Kombat for home consoles to feature online multiplayer.
The Konquest Mode in Mortal Kombat: Deception is completely overhauled into an adventure/fighter hybrid with light RPG elements. The story is a prologue to the main game's story, as the player takes control of Shujinko in his quest for the six Kamidogu artifacts under request by Damashi, a being who was sent by the Elder Gods. (Which later revealed to be false, as Damashi is actually an avatar of the antagonist Onaga).
Like the previous game, Konquest Mode is the primary way of earning "koins" for unlocking bonus content in The Krypt. However, some bonus content must be unlocked by accessing certain areas within Konquest Mode.
In a homage to Archon: The Light and The Dark, Chess Kombat is a unique Chess-based mini-game that combines the strategy of Chess with the combat of Mortal Kombat: Deception. The objective of the game is to eliminate the Leader piece. Players begin by choosing five characters to represent each of their five types of pieces:
- Leader - The player's "King" and most valuable character, but can only move one space at a time in any direction. Base health is at 80% and carries three "Combo Breakers".
- Champion - The player's two most powerful characters on the board. They have the most manueverability on the board (can move as far as they can in any direction) and the most health (with a maximum base health). They carry two "Combo Breakers" each.
- Sorceror - Although weak (with a base health of 30%), the two Sorceror characters can cast unique spells. They can only move two spaces to the front, back, or side and carry one "Combo Breaker" each.
- Shifter - The player's three Shifter characters change into their opponent's character just for that battle. (Unless they fight another Shifter, in which both Shifters do not change and start with full health) Their base health is at 50%, they can move five spaces in any direction, and they carry two "Combo Breakers" each.
- Grunt - The player's eight "Pawn" characters with no special qualities. They can move two spaces to the front, back, or side or one space diagonally, carry one "Combo Breaker" each, and have a base health of 40%.
After placing hidden "Trap" squares, in which opponents landing on it would automatically be removed, players take turns moving each of their sixteen pieces around the 10x10 board. There are also two "Power Cell" squares, which landing on it would give a health bonus to the entire team. Sorcerors can also cast a spell on their turn. One Sorceror controls the Defensive (Blue) spells while the other controls the Offensive (Red) spells. A spell can only be cast once per game.
- Heal (Defensive) - Heals one friendly piece up to their base health.
- Teleport (Defensive) - Teleports any friendly or enemy Grunt, Shifter, or Champion anywhere on the board.
- Resurrect (Defensive) - Brings back any defeated friendly piece.
- Protect (Defensive) - Protects any friendly piece from attacks and spells for three turns.
- Kill (Offensive) - Kills any enemy Grunt or Shifter.
- Imprison (Offensive) - Prevents an enemy piece from moving or casting spells for three turns.
- Exchange (Offensive) - Switches any two friendly or enemy Grunts, Shifters, or Champions.
- Sacrifice (Offensive) - Kills any friendly piece (except the Leader) in order to heal another friendly piece.
When a player moves his piece to a square occupied by an opponent's unprotected piece, the battle between them would begin. On top of their base health, attacking players gain a 10% health boost, teammates occupying a "Power Cell" gives a 25% health boost for each occupied "Power Cell", and defending players directly on a "Power Cell" start with 100% health. The combat plays like a simple Versus Mode round. The winner of the round occupies the square while the loser piece is removed from the board. Any health below the base health lost for the winning player is carried between matches.
In a homage to Super Puzzle Fighter II Turbo, Puzzle Kombat is a versus puzzle game where players control a pair of blocks that drop into an 8x12 playing field.
The objective is to clear blocks of the same color by using a "Breaker" block (as indicated by the Mortal Kombat dragon logo) or a "Bomb" block. Clearing blocks and making combos adds blocks to the opponent's playing field while adding to the player's Super Gauge. When the Super Gauge is filled, the player has a limited time to use their Super Attack, which can clear the player's blocks, add blocks to the opponent, or temporarily handicap the opponent. The game features super-deformed versions of 12 of the game's characters, each with their own unique Super Attack:
- Scorpion - Jumbles the opponent's blocks.
- Baraka - Destroys all blocks on the left- and right-most columns of the player's field.
- Nightwolf - Removes all "Breaker" blocks on the opponent's field.
- Ermac - Removes much of the top-most blocks of the player's field.
- Sindel - Arranges all of the player's blocks so all colors are lined up next to each other.
- Sub-Zero - Temporarily freezes all of the opponent's blocks, preventing them from being destroyed by "Breaker" blocks.
- Bo' Rai Cho (unlockable) - Removes much of the bottom-most blocks of the player's field.
- Kenshi (unlockable) - Temporarily makes all the opponent's blocks invisible.
- Mileena (unlockable) - Destroys all blocks in the two middle columns of the player's field.
- Jade (unlockable) - Makes rows of blocks rise from the bottom of the opponent's field.
- Kabal (unlockable) - Drops two "Bomb" blocks randomly down the player's field.
- Raiden (unlockable) - Rains blocks on the opponent's field.
Mortal Kombat: Deception includes 12 starting playable characters, 12 unlockable characters, 8 unplayable Konquest Mode opponents, and 1 unplayable boss.
New characters include the protagonist Shujinko, Ashrah (a demon who searches for redemption), Hotaru (a warrior of Orderrealm), Darrius (the leader of a resistance in Orderrealm), Dairou (a mercenary sent by Darrius to kill Hotaru), Havik (a cleric from Chaosrealm), Kobra (a bloodthirsty martial artist), and Kira (a female Black Dragon recruit). The final boss of the game is Onaga, the Dragon King and former emperor of Outworld. Noob Saibot and Smoke fight together as one "fighter" with multiple "fighting styles".
The unlockable characters in Mortal Kombat: Deception are either unlocked by opening certain Koffins in The Krypt or by finding special areas in Konquest Mode. Konquest Mode also includes seven unplayable opponents from Mortal Kombat: Deadly Alliance and one new unplayable opponent (Monster). Other Mortal Kombat characters, such as Stryker, make an appearance in Konquest Mode.
The GameCube and PSP versions of Mortal Kombat: Deception include two new characters: Goro and Shao Kahn. The GameCube version also unlocks six of the locked characters from the start. The PSP version also includes four bonus characters from Mortal Kombat: Deadly Alliance: Frost, Jax, Kitana, and Blaze. All playable characters in the PSP version are also unlocked from the start.
- Jade (unlockable in all except the GameCube and PSP versions)
- Kenshi (unlockable in all except the PSP version)
- Sindel (unlockable in all except the PSP version)
- Havik (unlockable in all except the GameCube and PSP versions)
- Raiden (unlockable in all except the PSP version)
- Li Mei (unlockable in all except the GameCube and PSP versions)
- Bo' Rai Cho
- Noob-Smoke (sub-boss, unlockable in all except the GameCube and PSP versions)
- Tanya (unlockable in all except the PSP version)
- Shujinko (unlockable in all except the PSP version)
- Hotaru (unlockable in all except the GameCube and PSP versions)
- Kira (unlockable in all except the GameCube and PSP versions)
- Liu Kang (unlockable in all except the PSP version)
- Onaga (unplayable boss)
- Goro (only available in the GameCube and PSP versions)
- Shao Kahn (only available in the GameCube and PSP versions)
- Blaze (only available in the PSP version)
- Frost (only available in the PSP version)
- Kitana (only available in the PSP version)
- Jax (Konquest Mode opponent, only playable in the PSP version)
- Drahmin (unplayable Konquest Mode opponent)
- Johnny Cage (unplayable Konquest Mode opponent)
- Kung Lao (unplayable Konquest Mode opponent)
- Monster (unplayable Konquest Mode opponent)
- Nitara (unplayable Konquest Mode opponent)
- Shang Tsung (unplayable Konquest Mode opponent)
- Sonya (unplayable Konquest Mode opponent)