Same-Actor Crossover

Same-Actor Crossover is a crossover that features two characters who are played by the same actor. A story where characters played by different actors supposed to be one and the same are not same-actor crossovers, but same-actor fusions. A notable example of this trope is Stilinski Twins from Teen Wolf fandom.
==Different types==
This crossover can be achieved in several ways:
* Family: The characters may meet because they are related; for instance, a story where two characters are cousins, long-lost siblings, or even twins. It's the most common in gen fics, but also happens in fics that feature a pairing.
* Doppelganger: If the fanfic features a pairing, it may pair up two characters played by the same actor. This is sometimes called doppelganger fic or doppelganger porn, although doppleganger fic does not always involve a crossover.See for instance A Perfect Mirror by Gin/backinblack, a Dark Angel story which pairs off two characters played by Jensen Ackles who are, canonically, clones, thus achieving doppleganger porn without a crossover.) 
**In another variant, a character meets, and it's often paired with, a character identical to their partner or friend, for whom the first character may or may not have feelings. The second character is a character played by the same actor that plays the partner.
* Both characters may be the same person: In some cases, the two characters from different shows are written as the same person, just under different names and sometimes in different time periods. 
**Long-lived characters may have assumed different identities over time. For example, in Queen of Swords, a show set in 19th century California, two of the supporting cast were played by the same actors who played Methos and Kronos in Highlander (Peter Wingfield as Dr. Helm and Valentine Pelka as Col. Montoya). One of Methos' common past professions in canon and fanon was medical doctor, and several stories were written where Dr. Helm was one of Methos past personae. Montoya was often written as Kronos for a reprise of one of the secondary Highlander slash pairings. The fact that Highlander canon had Duncan MacLeod in America at the same time helped seal this crossover's popularity.
**In thrillers stories, a character may maintain several identities at the same time. In Once a Thief the character of Victor Mansfield was played by the same actor who played Alex Krycek on The X-Files. The OaT character was a secret government agent who used to be a cop before he was arrested and spent time in prison and Krycek started out as an FBI agent who is later revealed as a double agent. Krycek disappears for longer periods of time just to suddenly resurface for a few episodes and in same-actor crossovers one explanation for this is his Vic Mansfield identity. 
** Personality Modification: The character may have become another person due to voluntary or involuntary "reprogramming"; this is a common trope in crossovers involving characters from Dollhouse and same-actor characters from other shows. For example, several Dollhouse stories have depicted Echo (played by Eliza Dushku) as a new personality imprinted onto the Buffyverse's Faith.
* Cloning: In the science-fiction genre, clones may be used to explain the resemblance. In Once a Thief's Vic is often written as a Krycek clone. In Highlander the character of Cory Raines was also played by Nick Lea, the Krycek actor. Cory was a Robin Hood-like character who stole from the rich to gave it to the poor and that fit well with one fannish interpretation of Krycek. That's why they are sometimes written as the same person too.
* Shape-Changing: Sources with canon shape-changers may use them to explain why a character from another show is actually the same person, regardless of any dissimilarities in the portrayal of the characters. This trope is often seen in crossovers involving Angel's Illyria (played by Amy Acker), who might thus take the place of Root from Person of Interest, "The Cellist" (Agents of SHIELD), etc.
In some cases, several of the above could be used at the same time. 
===Same Actor Fic===
====Family====
* Sugar is Sweet by Russet McMillan: Jim Ellison (The Sentinel) meets Mack Wolfe, his long-lost twin brother of One West Waikiki; both are played by Richard Burgi.
* Tarlan's Endless Road series, is a Stargate Atlantis/Century Hotel crossover in which Century Hotel's Michael turns out to be Rodney's long-lost granduncle, shunned by the family for living with another man, John's supposedly-dead grandfather. John and Rodney are also a couple. Both Michael and Rodney are played by David Hewlett.
====Doppelganger====
* Red Light by Jane Davitt: Jim Ellison (The Sentinel) meets and sleeps with Karl Mayer (Desperate Housewives); both are played by Richard Burgi.
* Until You're Human (88 drabbles of Double Joy) by ShyBob: River Tam (Firefly) meets Cameron (Terminator: The Sarah Connor Chronicles); both are played by Summer Glau.
* In the zine A Week in L.A., Dirty Harry Callahan leaves his lover, Johnny, in San Francisco to take a case in Los Angeles. He is shocked when he meets Hutch. "After twenty years on the force, he thought he was immune to surprises, but he was wrong. He stared at Ken Hutchinson in amazement. The face, coloring, eyes, even the height and build. Johnny. The man looked exactly like Johnny." Both men, of course, are played by David Soul. Another example in this fandom is Double Play (1979)
* The Lily-White Boys by L.R. Bowen: Tom Paris of Star Trek Voyager meets and sleeps with Nick Locarno from Star Trek TNG--maybe. The story plays with the fact that not only are both roles played by Robert Duncan McNeill, but the character of Paris was based on that of Locarno.
* Fare Thee Well by Tammy Morrison: Nick Knight (mortal after the events of the series finale) moves to Black Harbour with Natalie Lambert (now his wife), where they meet Nick Haskell's family. Both Nicks (the first from Forever Knight and the second from Black Harbour) were played by the same actor, Geraint Wyn Davies.
*Dawn In Rome by Roz Kaveney: Dawn Summers (Buffy) is kidnapped by gangsters who are actually after rock star Celeste (Six Feet Under), also played by Michelle Trachtenberg, while Celeste is kidnapped by demons who want The Key. F/F and F/F/F.
* by Devilc, The Losers crossover fic where Jake Jensen gets transported to the MCU universe. Both him and Steve Rogers are played by Chris Evans.
*Brief Encounter (Carol Aird/Florence Zimmermann) by ShadowHaloedAngel, 2019, is probably one of the first Carol Aird/Florence Zimmermann fics on the Ao3. The characters Carol Aird from the movie Carol and Florence Zimmermann from The House with a Clock in Its Walls were both played by Cate Blanchett.
====Same person====
 
* Crossroads is a 1994 Beauty and the Beast (TV)/Terminator zine in which Catherine Chandler interacts with Sarah Connor. 
* The Brendan Hypothesis by Smitty is a Stargate Atlantis/Thoughtcrimes crossover where NSA agent Brendan Dean (played by Joe Flanigan) was McKay's lover until he was killed. Years later, McKay meets John Sheppard (also played by Joe Flanigan), who looks exactly like Dean, and he sets to prove they're the same person. It's a McKay/Sheppard story with a twist.
*In the series One out of many and all of them the same, all of Jeremy Renner's previous character roles have been Clint Barton undercover. (For more, see the Six Degrees of Jeremy Renner trope)
*Faith and Lies By Teri; "Something stirs-up memories of Faith's past. Crossover with “True Lies.” Slight X/F." Buffy/True Lies (Characters played by Eliza Dushku)
* stellarmeadow's Heartbeat is a Hawaii Five-0/Moonlight crossover. Mick St. John was the biological father of John McGarret, who was adopted by his maternal grandparents after Mick became a vampire. After he took the cure and was human again, he became Steve McGarrett, John's son. It's a Steve/Danny story.
* Boy Falls From the Sky by lc2l. The Social Network/The Amazing Spider-Man fusion.
====Cloning====
* Mulder in the Middle by Orithain: X-Files crossover series where Mulder gets to meet (and sleep with) several different characters that were all played by Nicholas Lea, the actor who played Krycek on The X-Files. There is also a casefile that explains it all: The characters from The X-Files (both of them), Once a Thief, Xtro II, Moloney, Lonesome Dove, and Sliders are all Krycek clones. In the end the pairing included nine people, seven of them played by the same actor (the eighth was an OMC Krycek!clone).
===Split OTPs===
A common variation of the Same Actor Crossover takes one half of a popular OTP and pairs them off-- not with their usual partner, but with someone who looks almost identical to that partner. These types of stories are extremely common in 6 Degrees of Canada and Stargate Atlantis (Hewligan), among others.
* Northern Comfort by Kellie Matthews: Benton Fraser (due South) meets Billy Talent (Hard Core Logo), who bears a strong resemblance to his partner Ray Kowalski; both Billy and Ray are played by Callum Keith Rennie.
* Desperate Times by Hurry Sundown: Ray Kowalski (due South) meets Geoffrey Tennant (Slings & Arrows), who bears a strong resemblance to his partner Fraser; both Geoffrey and Fraser are played by Paul Gross.
* True Faith by Zulu: Buffy (Buffy the Vampire Slayer) meets Tru Davies (Tru Calling) and mistakes her for fellow Slayer Faith (who seems to finally return her feelings); everything gets more complicated when the true Faith also arrives in town. Both Tru and Faith are played by Eliza Dushku.
* Nine Lives, Cat's Eyes by veronamay: Sam Winchester (Supernatural) meets Alec (Dark Angel), who looks like a younger version of his brother Dean; Alec and Dean Winchester are played by Jensen Ackles.
* The Flying Doctor by TealTumbleweed: Martin Crieff/John Watson -- John follows Sherlock to Boston. So when a man unexpectedly falls ill during the flight, there is, in fact, a medical doctor on board. Martin Crieff's character (from the radio comedy Cabin Pressure) is voiced by Benedict Cumberbatch, who also plays Sherlock Holmes in BBC's Sherlock.
* Morgan by Judith Proctor: Avon (Blake's 7) meets Welsh sheep farmer Morgan (Morgan's Boy), who resembles Blake; both are played by Gareth Thomas.
* Interludes by S. Clark: Natalie Lambert (Forever Knight) has a fling with Nick Haskell (Black Harbour) while on holiday trying to get over the fact that Nick Knight has moved on. Both Nicks were played by Geraint Wyn Davies.
==Meta==
* Same Actor Crossovers (response to Lucy Gillam) by Shomeret at The Fanfic Symposium argues that fans who write same-actor crossovers court disaster in case their story should tip over the edge and fall into the "delusional thinking" of RPF, but that same-actor crossovers done correctly are not in themselves "ethically wrong". (1999) Others disagree.
==Art Examples==
File:Crossroadshamilton-2.jpg|from Crossroads, a 1994 Beauty and the Beast (TV)/Terminator zine in which Catherine Chandler interacts with Sarah Connor. 
Image:johnbookindyhan.jpg|John Book and Han Solo and Indiana Jones, by Zawiah
File:Doubleplayloose-2.jpg| inside Double Play, a 1979 Starsky and Hutch crossover with Harry/Johnny, the artist is TACS 
File:Obsession2-7.jpg|from Obsession #2, artist is James Doyle, subjects are James Kirk (TOS) and T.J. Hooker (1982)
File:Laura baily voice actress by damee momma ds1yga-fullview.jpg|Fanart from 2007 by DaMee-Momma, showing three characters voice-acted by Laura Bailey wearing eachothers' outfits.
==References==
Category:Crossover