Tekken Tag Tournament (鉄拳タッグトーナメント, Tekken Taggu Tōnamento) (commonly abbreviated as Tekken Tag and TTT) is the fourth main installment in Namco's Tekken fighting game series. It, however, is not canonical to the Tekken storyline.
Tekken Tag Tournament was originally released as an arcade game in 1999 before becoming a launch title for the PlayStation 2 in 2000. The arcade version operated similarly, but ran on a 32-bit graphics engine like Tekken 3. It received upgraded graphics when it was ported to the PlayStation 2. Its sequel Tekken Tag Tournament 2 was released in 2011. A remastered version of the game titled Tekken Tag Tournament HD was released for the PlayStation 3 in November 2011, as part of Tekken Hybrid.
Continuing the fighting mechanics from Tekken 3, Tekken Tag Tournament sees players battling in teams of two characters. At any point in the match, the player can hit a tag button to swap out with their other fighter, allowing the resting fighter to recover some lost health. The tag can be implemented in many ways, such as in between combos or utilizing special throws. At times when a resting fighter's lifebar is flashing, that character can be tagged in to be given a temporary boost in strength. Unlike other tag games such as Capcom's Vs. series, players are defeated when only one of their fighters lose all of their health, requiring players to be strategic about tagging their fighters. In the event of a timeout, the team with the most accumulative health remaining wins the round.
The game features over 35 characters that previously appeared in Tekken 2 and Tekken 3. In addition, there is a boss character, Unknown, who is similar to Tekken 3's Mokujin in that she can randomly imitate any character's fighting style, albeit she is able to change her style any time during the fight. The PlayStation 2 version added enhanced graphics and various modes, including 1-on-1 mode, in which players only choose one fighter each, and Team Battle, where players choose up to eight battles and play with the tag rules, with each new character replacing the one that was defeated (the remaining fighter must fight on his/her own). Also featured is the "Tekken Bowl" mode, a bowling minigame where each character has different attributes.
The arcade and console versions of Tekken Tag Tournament differ slightly. The arcade version ran on a 32-bit engine, utilizing the graphics engine of Tekken 3. These graphics ran using the Tekken 3 PCB board, based on the PlayStation hardware. The console version ran on a highly updated engine, utilizing the PlayStation 2's graphics processor. The game does not run on a 32-bit engine, yet on a new and updated engine highly similar to that found on Tekken 4. The background designs and BGMs differed too, as the console version has new updated tracks, while the arcade version was based on MIDI tracks with an instrumental backing. Unknown is not playable on the arcade version, yet the character is on the PlayStation 2 version. The arcade version also allows players to only select the alternative colors that have been added to the costumes at first, while the normally colored ones are unlocked when the bonus characters are. There are also crucial differences concerning the playability of the characters, as some moves or attacks are much more efficient in the arcade version than in the console version and vice versa.
Tekken Tag Tournament, being a non-canon game, features no storyline. It is more of a compilation of the Tekken series giving fans the opportunity to play as almost every character in the series up to that point, including many of those that had apparently been missing in the main Tekken storyline. Of all the returning characters, Kazuya Mishima was the most heavily promoted, since he featured prominently on the game's cover art and promotional material, despite his absence from the previous entry in the Tekken series (he would return in Tekken 4).
When Arcade mode is completed, a real-time ending is shown over the credits for the main character (i.e. the first character chosen when selecting the two fighters). The exception to this is Unknown's ending, which is a FMV.
As the game was made to be a compilation of previous games, the game include nearly every character from the original Tekken up to Tekken 3, including those who were canonically missing in the current canonical game Tekken 3. All of them have improved appearance and movesets to make them on par with the Tekken 3 characters.
Additionally, the game adds two new characters, both of them being mimic characters: Tetsujin, a metallic version of Mokujin, and Unknown, a mysterious woman who is controlled by the "Forest Demon" and also serves as the final boss of the game. Both characters seldom appear in future games, with Unknown resuming her role as final boss in the sequel Tekken Tag Tournament 2, while Tetsujin is featured as a boss in the free-to-play Tekken Revolution.
The only absent characters in the game that were playable in previous entries of the series are the original Jack, the first King, the first Kuma, Marshall Law, Dr. Bosconovitch, and Gon. Dr. Bosconovitch, however, makes a cameo appearance in the Tekken Bowl mode as a spectator.