Jump to content

Street Fighter X Tekken

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by 67.175.85.156 (talk) at 20:46, 29 September 2012. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Street Fighter X Tekken
Street Fighter X Tekken
Cover art for Street Fighter X Tekken
Developer(s)Dimps / Capcom
QLOC (PC)
Publisher(s)Capcom
Producer(s)Yoshinori Ono
Platform(s)PlayStation 3, PlayStation Vita, Xbox 360, Microsoft Windows,[4] iOS
ReleasePlayStation 3, Xbox 360
Microsoft Windows
May 11, 2012[3]
PlayStation Vita
iOS
September 19, 2012
Genre(s)Fighting

Street Fighter X Tekken (ストリートファイター X 鉄拳, Sutorīto Faitā Kurosu Tekken) (pronounced Street Fighter Cross Tekken) is a crossover fighting game developed by Capcom and released in March 2012 for the PlayStation 3 and Xbox 360, in May for the PC and in October for the PlayStation Vita. The game features characters from both the Street Fighter franchise and Namco's Tekken series.

As the game was made by Capcom, with Namco being involved more in the licensing of the Tekken cast, the gameplay is based on the 2D gameplay of Street Fighter, as opposed to the Tekken series, featuring projectile moves such as the Hadouken. Namco is currently producing their own take on the crossover, Tekken X Street Fighter, which will follow their 3D style of gameplay.[5]

Gameplay

Being developed by Capcom, the core gameplay is similar to that of the Street Fighter series, incorporating elements such as Super Combos and EX Attacks. Players each choose two fighters from the Street Fighter and Tekken series, both sets of characters are controlled using the Street Fighter six-button system, however, it has been revealed that the Tekken characters will be able to perform Tekken style combos using the primary four buttons in a similar fashion to the Tekken four-button system.[6] These fighters can be switched out normally, or during certain combos. As fights go on, players build up power in a three sectioned meter at the bottom of the screen referred to as the "Cross Gauge", which allow the player to perform various techniques depending on how much of the gauge is filled, such as EX Attacks, Cancels, Super Arts and various Cross techniques detailed below. Additionally, each fighter possesses one special attack that can be charged into an EX Attack or Super Art without any cost to the Cross Gauge. As opposed to the other crossover fighting games released by Capcom, in which the player must eliminate all the opponent's fighters to win, victory conditions are more similar to Tekken Tag Tournament, in which the first player to have one of their fighters' health bars reduced to zero loses the round, thereby the player who wins the most rounds wins the match.

The tag team element of the game is heavily emphasized, with players being able to switch between the two characters in their team in a variety of manners.[7] Switch Cancel allows players to switch partners in the middle of a combo, whilst Cross Rush combos involve launching the opponent into the air before swapping partners and continuing the combo. Cross Arts, which require a full Cross Gauge, allows players to chain together each character's Super Combo in one straight attack, whilst the Cross Assault mechanic allows players to simultaneously control both characters in their team until the Cross Gauge runs out.

Street Fighter X Tekken features two new game mechanics: the Gem System and Pandora Mode. Players equip up to three gems to their characters, which provide different stat boosts depending on the type of gem. Six varieties of gems exist: attack, defense, speed, vitality, assist, and Cross Gauge. Each gem and its effects are designated by a specific color, and will activate as the players fulfill certain conditions during battle. When a character on a player's team has less than 25% health remaining, that character can be sacrificed in order to activate Pandora Mode, which gives the remaining fighter increased strength and an infinite Cross Gauge. However, this state has a time limit and the player will automatically lose if he/she cannot defeat the opponent before the Pandora state runs out.[8]

The game features various online options. Two players can battle on the same team, one controlling each character, and face off in four player matches. Scramble mode allows four players to fight simultaneously in pairs of two. The game will also support online training modes which can be played competitively or cooperatively with two players, as well as support the Fight Request feature.

Other Capcom games are referenced in the game, such as Dino Crisis, which has a stage based around one of its levels.[9]

Plot

The center of the conflict between the Street Fighter and Tekken universes is a cubical object that crash-lands in Antarctica. The object is of a mysterious origin and researchers worldwide are unable to determine what purpose it serves. The only thing that can be understood is that when beings come into conflict around this object, it releases a water-like energy that brings more power to the combatants. Due to the object's tendency to react to conflict between beings, they name it "Pandora".[10] Whilst a standard story is given to most combinations of fighters, specific teams, such as Ryu and Ken or Kazuya and Nina, receive their own unique story elements and rival battles.

Characters

The following characters are available as playable characters in the game. The PlayStation 3 and PlayStation Vita versions feature 5 exclusive playable characters, including Cole MacGrath from Sucker Punch's Infamous series; Sony mascots Toro Inoue and his rival Kuro, who dress up as Ryu and Kazuya respectively; Pac-Man, who pilots a Mokujin-style mech; and Mega Man, who takes his appearance from the North American box art for the first game.[11][12][13][14][15] Both Mega Man and Pac-Man became available as free downloadable content for the PlayStation 3 version on the 13th of March.[16] Street Fighter's Dan, seen in the initial Street Fighter X Tekken reveal trailer, makes a non-playable appearance as the instructor in the game's tutorial mode.[17] Ono stated that there is no exclusive character for the Xbox 360 version, claiming "We do have the exclusive characters for the Sony platform. We have Cole, the two Sony cats, Kuro and Toro. But basically for the Xbox 360, we were in discussions with them (Microsoft) for which character to put in as an exclusive, but we weren't able to decide on a character because of differences in timing and things like that."[18]

The PS Vita version will include a code to download 12 additional fighters, six from each side.[19][20] All 12 characters have been released as DLC for the PlayStation 3 and Xbox 360 on July 31, 2012, and are set to be released for the PC in last September, before the Vita version's launch.[21] The owners of the PlayStation 3 version are able to obtain the characters for free if they download them through the PlayStation Vita version.[22] All together, the Sony versions will have 55 playable characters available, giving Street Fighter x Tekken the second biggest roster in a Capcom fighting game after Marvel vs. Capcom 2: New Age of Heroes, which had 56 characters in all.

Street Fighter Tekken Guests
Ryu 3 Kazuya 3 Mega Man 2
Ken Nina 3 Pac-Man2
Chun-Li 3 Asuka Toro2
Cammy Lili Kuro2
Guile3 Heihachi Cole2
Abel Kuma
Dhalsim3 Paul3
Sagat Law
Rolento King3
Ibuki Marduk
Poison Hwoarang3
Hugo3 Steve
Rufus Bob
Zangief Julia
Vega Yoshimitsu
Balrog Raven
M. Bison Jin
Juri Xiaoyu
Akuma Ogre
Sakura1 Lars1
Blanka1 Alisa1
Guy1 Bryan1
Cody1 Jack-X1
Elena1 Christie1
Dudley1 Lei1
Notes:

^1 Downloadable content for PlayStation 3, Vita, Xbox 360 and PC.
^2 Exclusively for PlayStation 3 and PlayStation Vita.
^3 Confirmed for iOS Version

Soundtrack

Note that all of these songs are only featured in cinematic trailers, with "Honest Eyes" appearing in the introduction cinematic on the game disk.

Development

Yoshinori Ono (left) and Tekken producer Katsuhiro Harada (right) talking about the plans of the crossover games at San Diego Comic-Con International 2010.

Prior to tournament EVO 2010 at Las Vegas, Nevada, producer Yoshinori Ono was teasing a yet announced game which was initially believed to be a new Darkstalkers entry.[23] Before EVO 2010's Super Street Fighter IV finals, Ono was confronted by Tekken producer Katsuhiro Harada on stage after teasing more of the game that would officially be announced at the 2010 Comic-Con.

During the Super Street Fighter IV panel at Comic-Con, Harada appeared out of the crowd and went towards the stage while handing out free copies of Tekken 6, which was met with cheers and boos. Ono and Harada then confirmed the existence of Street Fighter X Tekken.[24] Both the teaser trailer and early gaming footage of Street Fighter X Tekken was also shown at Comic-Con.[24] During the announcement, Harada also revealed that he has a related project under way, which is being developed by Namco. As Namco is in charge of production of this game, the gameplay will be similar to that of Tekken.[24]

Namco and Capcom previously collaborated on a role-playing game, the 2005 Japan-only release PlayStation 2 Namco × Capcom, which featured characters from various games released by both companies. It has been stated by Yoshinori Ono that a 3DS version of the game "should happen" but nothing has been officially revealed. Information on a 3DS version was expected to be provided at Captivate 2011, but no mention of a 3DS version was made. The game was announced for PlayStation Vita at E3 2011. Downloadable content will be cross-compatible between both the PlayStation 3 and Vita versions of the game.[25]

Marketing

Prior to the release of Street Fighter X Tekken, Capcom allowed players to try the game at several Fight Night events. At one such event, Capcom raised over £5,000 for UK charity GamesAid.[26]

In collaboration with fighting game production groups iPlayWinner and Team Spooky, Capcom announced a special reality show titled Cross Assault, broadcast live via Twitch.tv. The show had ten players chosen by video submission to participate for either Team Street Fighter or Team Tekken in challenges based on Street Fighter X Tekken. The final four players earned Evo Championship Series seeding points for the game's appearance at Evo 2012 with the last player standing winning a $25,000 grand prize. The show ran from February 22–28 with the final taking place at Road to Evo Tournament Season event, Final Round on March 3, 3 days before the game's release.[27][28][29] The series received criticism for featuring sexual harassment of its female players, particularly from team coach Aris Bakhtanians.[30]

In PlayStation Home, the PS3's online social gaming platform, users could pre-order Street Fighter X Tekken directly from Home and receive the in-game bonus, "Boost Gem Trial Pack 1", as part of Home's Total Game Integration. In addition, a portion of The Hub (North America's central meeting point) was redesigned featuring a Street Fighter X Tekken fighting game where users could use their Home avatars to fight each other and unlock Ryu and Kazuya costumes for their avatars (which allow users to throw fireballs and perform custom jump kick attacks) by completing all ten challenges.[31] On July 25, 2012, the Total Game Integration received its own dedicated game space.[32]

Retail versions

The Special Edition features a Build-It-Yourself Arcade Cabinet Bank (approximately 5"H), prequel comic book by UDON and 36 gems, which includes all pre-order DLC packs (World Warrior, Iron Curtain, Lightning Legs) plus an exclusive Special Edition DLC pack (King of Iron Fist).[33] The Special Edition also comes with nine exclusive gems (Cross Arts DLC) only available as a pre-order bonus for the edition, making it total of 45 gems if the edition is pre-ordered.[34]

The Collectors Edition features the World Warrior DLC, which includes nine gems, all of which provide characters with different attributes and properties. Also included is a 46 track original soundtrack spanning two discs and a 44 page art book.[35]

In the Asian market the special edition includes DLC for a complete pack of gems, a 2-disc 46 soundtrack, 41 character cards with art on one side and move details on the other, and Bobble Budds bobble heads modeled after Street Fighter producer Yoshinori Ono and Tekken producer Katsuhiro Harada.[36]

In Australia the three big game retailers, EB Games, JB Hi-Fi and Game, shared three pre-order bonuses. EB Games offers the exclusive Special Edition. JB Hi-Fi offers the standard edition, along with a 60 cm x 90 cm wall scroll featuring Ryu and Kazuya Mishima. Game offered the standard edition bundled with a Kazuya Mishima and Ken T-shirt.[37]

Unfortunately for North American PC gamers, Capcom senior VP Christian Svensson stated that there will be no North American retail release for the PC version. It will only be sold digitally through Steam only. However, Asia and Europe will get a retail box copy of the PC version. Reason behind this is that Capcom SF producer Ono stated he decided he does not want an on-disc DLC for the PC version and fears that hackers may crack the game and the DLC and create mods for this to happen.[38][39]

Reception

As of March 31, 2012, Street Fighter X Tekken has sold 1.4 million units worldwide, in contrast to Capcom's expectations that it would sell 2 million units.[57] It blamed the game's poor performance on the cannibalism of the fighting game genre - that is, too many fighting games launching within too short a time.[58]

Both console versions of Street Fighter X Tekken received positive reviews from critics. The game received an aggregated score of 84 from Metacritic for both its PlayStation 3 version and for its Xbox 360 version. The two versions received similar scores at GameRankings.

IGN gave the game a 9/10, calling it "a fantastic fighting game that nails the basic fighting mechanics while daring to take a few risks with the formula as we know it."[52] GameSpot gave the game 8.5/10 stating "Street Fighter X Tekken is fun for a wide range of players while still offering the complexity serious fighting fans have come to expect."[49]

GamesRadar gave the game 8/10, calling it "Another fast, fun, and technical Capcom fighting experience."[50] GameInformer gave the game 8.75/10 saying "moderate to hardcore players are going to find a lot to absorb in Street Fighter X Tekken, and players with patience will be rewarded for it."[48] Eurogamer gave the game 9/10 stating "This ripped, boisterous crossover game arrives in a blaze of creativity, one of an intensity rarely seen in Japanese game output of late. A fierce, passionate marriage then - but one that just might last."[46]

The Official PlayStation Magazine gave the game 9/10 saying "SFXT offers finely tuned and emergent action and a positively regal rumble of the genre's celebrated a-listers."[53] The Official Xbox Magazine gave the game 9/10, stating "The tag mechanic is brilliantly robust, there are loads of new moves to master and the Tekken characters slot in more comfortably than a bum in a favourite armchair."[54]

Controversy

The inclusion of characters on the disc that can only be used by paying more resulted in criticism by fans and publishers as gamers would pay an additional amount of money for something that was completed before release and on disc.[59][60] Capcom responded stating they intended to add the characters locked in the retail versions to save hard drive space.[59]

Another subject of criticism has been that online tag-team matches are not available for the Xbox 360 version although the feature was advertised and printed in the manual. Capcom stated this will not be fixed with a patch.[61]

See also

  • Tekken X Street Fighter, another fighting game featuring Street Fighter and Tekken characters currently being developed by Namco.
  • Street Fighter EX3, a previous tag-team game featuring Street Fighter characters
  • Namco × Capcom, a strategy RPG crossover by Namco released in 2005 with Namco's franchises.

References

  1. ^ Mike Jackson. "Street Fighter X Tekken out before April 2012". ComputerAndVideoGames.
  2. ^ "Capcom's Street Fighter X Tekken releasing March 9th in Europe". Retrieved 2011-10-17.
  3. ^ "Street Fighter X Tekken on Steam". Store.steampowered.com. 2012-05-11. Retrieved 2012-05-30.
  4. ^ SFxT confirmed for March, PC version announced – details. VG247 (2011-10-15). Retrieved on 2012-01-18.
  5. ^ Johnathan Holmes (July 24, 2010). "SDCC: Two Street Fighter/Tekken Crossover games announced". Destructoid. Retrieved July 24, 2010. [dead link]
  6. ^ Stephen Totilo. "How Street Fighter X Tekken Controls And Why It's Not Street Fighter Vs. Tekken". Kotaku.
  7. ^ "Street Fighter X Tekken Gameplay". Capcom.
  8. ^ Posted: Sep 15, 2011 (2011-09-15). "Street Fighter X Tekken Video Game, TGS 11: Pandora Mechanic Walkthrough | Video Clip | Game Trailers & Videos". GameTrailers.com. Retrieved 2011-10-11.{{cite web}}: CS1 maint: numeric names: authors list (link)
  9. ^ Stephen Totillo (April 12, 2011). "See The Battles Of Street Fighter X Tekken, Plus A Dino Crisis Wink". Kotaku. Retrieved April 12, 2011.
  10. ^ Ishaan (2011-09-13). "Street Fighter X Tekken Screens Show New Characters And A Very Angry Ryu". Siliconera. Retrieved 2011-09-19.
  11. ^ Fahey, Mike. "Street Fighter X Tekken Comes to the PlayStation Vita with an Infamous Addition". Kotaku.
  12. ^ Toro and Kuro to appear in Street Fighter x Tekken!. Capcom-europe.com (2011-09-14). Retrieved on 2012-01-18.
  13. ^ By Ishaan . September 14, 2011 . 1:07am (2011-09-14). "Sony Mascots Toro And Kuro Bring The Pain In New Street Fighter X Tekken Screens". Siliconera. Retrieved 2011-10-11.{{cite web}}: CS1 maint: numeric names: authors list (link)
  14. ^ "See Mecha Pac-Man and Fat Mega Man Beat Ass Galore in Street Fighter X Tekken". Kotaku.com. 2012-01-27. Retrieved 2012-05-30.
  15. ^ "Two more PS3/Vita exclusive characters revealed for Street Fighter X Tekken". Capcom-Unity. January 26, 2012. Retrieved January 26, 2012.
  16. ^ "Super Street Fighter Iv & Street Fighter X 鉄拳|オフィシャルブログ". Capcom.co.jp. Retrieved 2012-05-30.
  17. ^ "Saikyo X Kobusi Blog". Capcom. 2011-12-26. Retrieved 2011-12-26.
  18. ^ Jackson, Mike (2012-01-23). "Xbox News: Street Fighter X Tekken Xbox has no exclusive fighters". ComputerAndVideoGames.com. Retrieved 2012-05-30.
  19. ^ "Street Fighter X Tekken Comes to PS Vita This Fall With 12 New Fighters from Side Mission Gaming News". Gametrailers.com. 2012-02-21. Retrieved 2012-05-30.
  20. ^ "Cover art for Street Fighter X Tekken on the PS Vita, screens of new fighters - Oct. 23, 2012 release date". Eventhubs.com. Retrieved 2012-08-05.
  21. ^ "Street Fighter X Tekken's DLC characters coming to PC in September, improved button config in Marvel vs. Capcom Origins". Eventhubs.com. Retrieved 2012-08-05.
  22. ^ Posted by SFilp — March 5, 2012 at 1:12 p.m. PST (2012-03-05). "Capcom explains why Street Fighter X Tekken's 12 DLC characters were on disc, fighters available in the fall". Eventhubs.com. Retrieved 2012-05-30.{{cite web}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  23. ^ Michael McWhertor (July 12, 2010). "Street Fighter IV Creator Teases Comic-Con Timed Game Reveal". Kotaku. Retrieved September 7, 2010.
  24. ^ a b c Michael McWhertor (July 24, 2010). "Street Fighter X Tekken, Tekken X Street Fighter Revealed At Comic-Con". Kotaku. Retrieved July 24, 2010.
  25. ^ "PS3, Vita versions of Street Fighter X Tekken will share DLC". Capcom-Unity. September 26, 2011. Retrieved January 26, 2011.
  26. ^ Parfitt, Ben (2011-11-23). "Industry Fight Club smashes targets". Market for Home Computing and Video Games. Retrieved 2011-12-15. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  27. ^ Crisan, Neidel (2012-01-23). "Capcom Announces Street Fighter x Tekken Live Reality Show "Cross Assault" On Latest Episode of X the Line, Produced by IPW x TS". iPlayWinner. Retrieved 2012-02-02. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  28. ^ "Street Fighter x Tekken "Cross Assault"". Capcom. 2012-01-23. Retrieved 2012-02-02. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  29. ^ "Cross Assault Announces Seeding Points for Evolution 2012; Submissions Extended Until February 8th". shoryuken.com. 2012-01-03. Retrieved 2012-02-27. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  30. ^ "The PA Report - Sexual harassment as ethical imperative: how Capcom's fighting game reality show turned ugly". Penny-arcade.com. 2012-02-28. Retrieved 2012-05-30.
  31. ^ Locust_Star (2012-02-13). "Street Fighter x Tekken Hits PlayStation Home". SCEA. Retrieved 2012-04-28.
  32. ^ Peterson, Cade (2012-07-24). "PS Home Weekly Update: Street Fighter Total Game Integration Comes Back Home". SCEA. Retrieved 2012-07-27.
  33. ^ Pre-Order Special Edition – Street Fighter X Tekken. Streetfighter.com. Retrieved on 2012-01-18.
  34. ^ News: Street Fighter X Tekken release date, PC version confirmed. ComputerAndVideoGames.com (2011-10-15). Retrieved on 2012-01-18.
  35. ^ News: Street Fighter x Tekken Collectors Edition detailed. ComputerAndVideoGames.com (2011-12-16). Retrieved on 2012-01-18.
  36. ^ Street Fighter And Tekken Producers Bundled With Street Fighter X Tekken. siliconera.com. Retrieved on 2012-03-07.
  37. ^ Xbox News: Australian pre-order offers announced for Street Fighter X Tekken. ComputerAndVideoGames.com (2012-01-13). Retrieved on 2012-01-18.
  38. ^ Capcom Copying Street Fighter X Tekken From Xbox 360 To PC, Problems And All. cinemablend.com {2012-3-29}. Retrieved on 2012-3-29.
  39. ^ Capcom Removing On-Disc DLC From PC Version Of Street Fighter X Tekken cinemablend.com {2012-4-09} Retrieved on 2012-4-09.
  40. ^ "Street Fighter X Tekken for PlayStation 3". GameRankings. 2012-03-06. Retrieved 2012-05-30.
  41. ^ "Street Fighter X Tekken for Xbox 360". GameRankings. 2012-03-06. Retrieved 2012-05-30.
  42. ^ "Street Fighter X Tekken for PlayStation 3 Reviews, Ratings, Credits, and More". Metacritic. 2012-03-06. Retrieved 2012-05-30.
  43. ^ "Street Fighter X Tekken for Xbox 360 Reviews, Ratings, Credits, and More". Metacritic. 2012-03-06. Retrieved 2012-05-30.
  44. ^ Otero, Jose. "Street Fighter X Tekken Review for PS3, 360 from". 1UP.com. Retrieved 2012-05-30.
  45. ^ "EGM Review: Street Fighter X Tekken". EGMNOW. 2012-03-06. Retrieved 2012-05-30.
  46. ^ a b Parkin, Simon (2012-03-05). "Street Fighter x Tekken Review • Reviews • Xbox 360 •". Eurogamer.net. Retrieved 2012-05-30.
  47. ^ Maniago, Daniel (2012-03-06). "Street Fighter X Tekken Review for Xbox 360". G4. Retrieved 2012-03-06.
  48. ^ a b "Street Fighter X Tekken Review: More Than Just A Mash-Up - Street Fighter X Tekken - Xbox 360". www.GameInformer.com. 2012-03-06. Retrieved 2012-05-30.
  49. ^ a b March 5, 2012 12:06AM PST (2012-03-06). "Street Fighter X Tekken Review". GameSpot.com. Retrieved 2012-05-30.{{cite web}}: CS1 maint: numeric names: authors list (link)
  50. ^ a b "Street Fighter X Tekken review". GamesRadar. 2012-03-05. Retrieved 2012-05-30.
  51. ^ "Street Fighter X Tekken: Reviews, Trailers, and Interviews". Gametrailers.com. Retrieved 2012-05-30.
  52. ^ a b var authorId = "330509557" by Steven Hopper (2012-03-05). "Street Fighter X Tekken Review - Xbox 360 Review at IGN". Xbox360.ign.com. Retrieved 2012-05-30.{{cite web}}: CS1 maint: numeric names: authors list (link)
  53. ^ a b "Street Fighter X Tekken PS3 review". Official PlayStation Magazine. 2012-05-25. Retrieved 2012-05-30.
  54. ^ a b "Official XBOX Magazine | Street Fighter X Tekken review". Oxmonline.com. Retrieved 2012-05-30.
  55. ^ "Street Fighter X Tekken Review for PS3". VideoGamer.com. Retrieved 2012-05-30.
  56. ^ "Street Fighter X Tekken - Review". ElectricBloomWebzine. Retrieved 2012-05-30.
  57. ^ "Street Fighter X Tekken 600,000 Units Short Of Sales Expectations". Siliconera. May 7, 2012. Retrieved May 7, 2012.
  58. ^ Yin, Wesley (2012-05-15). "Capcom: sales of Street Fighter x Tekken "have fallen short of our plan" • News •". Eurogamer.net. Retrieved 2012-05-30.
  59. ^ a b Dransfield, Ian. "Capcom Includes Paid DLC On The Disc, Hilariously". Play. Retrieved March 16, 2012.
  60. ^ Sinclair, Brendan (March 16, 2012). "On-Disc DLC Outrage Is Off the Mark". GameSpot. Retrieved March 16, 2012.
  61. ^ Ciolek, Todd (March 7, 2012). "The X Button Gaiden Guided". Anime News Network. Retrieved March 16, 2012.

Template:Namco's X series