This article focuses on the interactions between everyone and Duncan.
Duncan's reputation amongst the other contestants is not easily defined as good or bad. As a rebellious delinquent, Duncan loves causing mischief and making jokes at others' expense. While a majority seems to dislike him, he is not as shunned as contestants such as Heather, Courtney, and Alejandro. He even gains enough support from them to win Total Drama Action in his ending of The Aftermath: IV. Duncan is known for being tough as nails, but there have also been plenty of instances where he is genuinely nice. He has a sweet side that he prefers to keep hidden from most of them, as when his good deeds are exposed, that has a tendency of getting him teased. This becomes part of a subplot in Total Drama All-Stars in which Duncan, initially labeled a villain and proud of it, is transferred to the Heroic Hamsters, where he finds the kindness of his new teammates (particularly Zoey) is making his own heroic side overpower his "bad boy" image. Nevertheless, Duncan is usually considered the lesser evil compared to the series' antagonists, and is still able to make a few friends (or at least at talking terms) with the other contestants.
In Total Drama World Tour, Duncan and Alejandro don't have much interaction due to Duncan quitting the game in the very beginning. However, after Duncan returns, Alejandro isn't very pleased because he knew Duncan would be a threat. As the game progresses, Duncan reveals that he doesn't fully trust Alejandro and attempts to get rid of him by turning Owen against him. Upon reaching the merge, however, Duncan, who wanted to get rid of Courtney as soon as possible, aligns himself with Alejandro. Eventually, Alejandro betrays Duncan by teaming up with Heather and eliminating Duncan in African Lying Safari. In Total Drama All-Stars, they are once again placed on the same team but do not interact much.
Due to them being on different teams as well as Beth's early elimination, the two of them are never seen interacting with each other. In Total Drama Action, the two had a minor conflict as Beth transfers her hatred from Duncan's girlfriend to him and attempts to vote him off several times in order to spite her. Duncan, on the other hand, finds Beth weird but had no problem with her otherwise. When they both of them make it to the final two, their new friendship starts to bloom for the first time and the two are even shown helping one another make it to the finish line. Although Duncan and Beth seem to have a small rivalry in the last finale, it appears to two of them develop respect for each other.
During Blaineley's song "Blainerific", Duncan states she is "so, so horrific". In Hawaiian Style, Duncan laughs at Blaineley when Geoff shows a video of her crashing into a roof of a house after taking the Drop of Shame. He also says that Blaineley has so much in common with Heather while giving her a Team Heather flag, possibly referring to a lack of support for both of them.
Duncan's mean nature made Bridgette hate him. Similarly, Duncan doesn't like Bridgette for distracting Geoff in episodes like the Brunch of Disgustingness when the contestants split into teams of boys and girls. After forming the guys' alliance in Hide and Be Sneaky, Duncan orchestrates Bridgette's elimination, seeing her as the biggest threat. Upon hearing this, Bridgette also plans to eliminate him but without help from Heather, Bridgette is eliminated instead. In Haute Camp-ture, Bridgette stated that Duncan is not as tough as he seems and brings up Duncan finding a new bunny for DJ in Who Can You Trust?, a rare admiration from Bridgette to him.
In Alien Resurr-eggtion, Duncan doesn’t allow Bridgette and Geoff to pair up with him, DJ, Gwen, and Trent due to their constant making out. During the elimination ceremony, Duncan most likely voted for either Geoff or Bridgette due to their make-out sessions annoying the other castmates. In The Aftermath: I, when Duncan is injured during "That's Gonna Leave A Mark!", Bridgette makes fun of him. In Mutiny on the Soundstage, Duncan is told by Chef that Bridgette mentions where is the weirdest place she and Geoff make-out many times but Duncan states that he doesn’t remember it as he doesn’t bother with a girl’s love life.
In order to encourage everyone to support Cody in Hawaiian Style, Bridgette shows the audience a video of Cody punching Duncan in Greece's Pieces though Duncan claims that he “took a dive” to make Cody feel better.
In You Regatta Be Kidding Me, Cameron, Duncan, Scott, and Zoey are all on the same raft for the challenge after Mike (Mal in reality) broke the remaining boats. When Cameron came up with a plan to make their raft faster (where they used Scott to lure Fang into pulling the raft), Duncan compliments him on it. However, in an earlier confessional, Duncan shows a little jealousy at Cameron, as even he can be a better villain than him.
Due to Chef Hatchet's militaristic nature and Duncan's rebellious delinquent persona, Duncan has a habit of getting on Chef's nerves. During Basic Straining, he finds various methods to get through Chef's challenges, but takes care to annoy Chef along the way. This is repeated in all episodes in which Chef is put in charge of the challenges, notably in Hide and Be Sneaky and Are We There Yeti? During the hiding challenge, Chef Hatchet has no trouble finding Duncan by using clues to his location. During Total Drama Action, Chef Hatchet keeps trying to make things difficult for Duncan, sometimes arguing with him over who should do what in the challenge such as in Riot On Set and The Sand Witch Project, even though he isn't supposed to interfere with either team. The conflict has somewhat boiled down since Total Drama Action.
Although the conflict between Duncan and Chris is relatively minor during the first two seasons, it quickly escalates in Total Drama World Tour when Duncan quits in the first episode after becoming frustrated with several factors. After taking the Drop of Shame, Duncan goes missing, leading Chris to take drastic measures to find him, including sending giant Drama Machines. Eventually, Chris found out that Duncan had been hiding in London and he is brought back to the competition by both his love interests. Once he is brought back into the show, Chris punished Duncan for quitting (and claimed he "owes him camera time") by making him sing every time he opens his mouth in Greece's Pieces. With the drama between Duncan, Gwen and Courtney going on, Chris decided to make Duncan stay in the game a little longer by pushing an intern off the plane even though Duncan received the most votes. In the next season, Duncan was brought back in Grand Chef Auto to demonstrate the challenge to the new contestants as well as to pay back the remaining camera time he still owes him. However, Duncan escapes and later destroy Mt. Chrismore. In Total Drama All-Stars, Chris kept making fun of Duncan's recent change of personality after he was transferred to the Heroic Hamsters. In retaliation, Duncan destroys Chris's mansion, prompting Chris to call the authorities to arrest Duncan and therefore, eliminating him from the season.
Prior to Total Drama World Tour, Cody doesn't seem to hate Duncan due to their lack of interaction. He playfully teases him for his fear in Phobia Factor and also cheers for him along with everyone else in Duncan's ending in The Aftermath: IV.
But upon Duncan's return in I See London... and beginning a relationship with Gwen, a conflict between the two has risen. Cody has been obsessed with Gwen since the first season and believes that with her and Trent no longer a couple, he can finally claim her. Upon discovering the kiss they share from Tyler in Greece's Pieces, Cody becomes jealous and angry that he has lost another chance and becomes hostile towards Duncan. Unaware of Tyler's announcement, Duncan returns from his challenge and mocks Cody's clothes. In response, Cody knocks out Duncan with a single punch.
In Picnic at Hanging Dork, Cody constantly annoys Duncan and does whatever he can to hurt Duncan. When Duncan has trouble trying to ride his emu, Cody shoves Duncan off, laughing and blowing a raspberry at him in response to his anger. Duncan eventually catches up to Cody and attempts to punch him but misses and is attacked by a kangaroo instead. Duncan eventually exacts his revenge by throwing a dingo at Cody, leading to Team Amazon's defeat. Unknowingly, their conflict also causes Gwen's elimination as Cody was supposed to vote for Courtney but because of his condition, he fails, leading to a tiebreaker challenge between Gwen and Courtney in which the former loses.
Due to Gwen's elimination, the conflict is put on a cease-fire where they each mourn Gwen's absence in their own way. However, Cody's hatred for Duncan hasn't let up even after Duncan's elimination and angrily kicks a giant stone statue of Duncan's head calls him a "Gwen stealer" in Rapa Phooey!. On the other hand, the conflict is somewhat resolved on Duncan's part as he supports Cody in the finale though it may be only because of Duncan's greater dislike towards the other two contestants.
Since the beginning of the series, Duncan and Courtney share a love/hate relationship with each other. Although she kept complaining about Duncan's lifestyle, Courtney is shown to have feelings for him but denies it whenever someone asks. After having some alone time together, the two share their first kiss and officially become a couple. However, their time together is short as Courtney is eliminated soon after, and they do not meet again until Duncan is eliminated. They were also separated for the next season as Duncan was one of those who qualify while Courtney doesn't.
Despite their relationship, tension rises when Courtney makes her debut midway in the second season after successfully suing the show as well having many unfair disadvantages. Additionally, Courtney was jealous of Duncan's friendship with Gwen and ruthlessly defeats him in many challenges. Nevertheless, the two of them still have feelings for each other, though Duncan is losing his patience. After a night discussing their relationship, Courtney decides to give Duncan a second chance provided he memorizes and correct everything she listed about him on a thirty-two page letter. Tired of Courtney bossing him around, Duncan voted her off in Top Dog and they broke up. Despite this, the two of them eventually reconcile after the finale.
In Total Drama World Tour, Duncan and Courtney are still in a relationship but he beginning to shift his feelings to Gwen instead after becoming tired Courtney bossing him around. After Duncan returns, he and Gwen share a kiss and Courtney eventually found out about the affair and broke up with him. For the remainder of the season, the two of them argue with each other every time they were in close proximity to each other. Determine to eliminate her, Duncan gains the help of Alejandro and successfully eliminates her in Chinese Fake-Out.
In Total Drama All-Stars, Courtney's dislike towards Duncan continues to the point where she pretends he doesn't exist at all, while Duncan desires to get Courtney's attention on several occasions. After Gwen dumps Duncan, both of his ex-girlfriends constantly make fun of him, refusing to listen to even when he tries to warn them about Mike not appearing as kind as he seems to be.
Despite their contrasting personalities, Duncan and DJ become friends in Total Drama Island, after Duncan defends DJ when their team needs to vote off someone and DJ being one of the prime candidates due to his lack of participation in the challenge. The two are joined by Geoff and are often seen hanging out together. After DJ loses his pet rabbit, Duncan doesn't want DJ to suffer the same fate as him when he lost his pet dog, Petey, and finds another rabbit for him, under the impression that the original one has come back. Later on, in the season, the three of them form the first guys' alliance with Owen when they realize that the girls outnumbered them. In the next season, Duncan and DJ are on the same team again after they are selected by Gwen. DJ is impressed by Duncan's performance throughout the season, especially when he replaces Gwen as their team's unofficial leader after Gwen is eliminated in The Chefshank Redemption. Despite their friendship, DJ chooses to vote for Beth to win the million dollars in The Aftermath: IV.
Though the two had had numerous changes with their friendship-hatred towards each other, Duncan is one of the few contestants who can tolerate Eva and has no real conflict with her. When Eva returns in No Pain, No Game, Duncan shows fear towards her and joins everyone in chanting Eva's name, when Bridgette gets a chance to pick someone to dare. Despite being afraid of her, he is one of the few contestants who didn't vote for her. In Haute Camp-ture, Eva admits that she likes Duncan's "style" when talking about the dodgeball challenge in Dodgebrawl.Bass had to face their first elimination ceremony in Not So Happy Campers - Part 2, and all the girls were glaring angrily at Ezekiel, Duncan told Ezekiel that he had "a lot to learn about the real world".
When Ezekiel was eliminated in Walk Like An Egyptian - Part 2, Duncan simply whistled and said, "sucks to be Zeke”. In African Lying Safari, after Duncan is tripped by Alejandro and falls into a bush of Serengeti Blood Berries, he attempts to clean himself at a small pond. Attracted by the scent of blood, Ezekiel burst out of the water and slashed Duncan across the chest, then pounced on him and beat him savagely. This eventually caused Duncan's elimination.
Duncan and Geoff's friendship always strayed in certain points. During Brunch of Disgustingness, Geoff (on the male team) helps Bridgette (on the female team) in one of the mini-challenges, which caused his team to lose the point for that mini-challenge. This got Duncan furious, however, they immediately made up after Chris' interjection, much to Bridgette's surprise. At the end of Hide and Be Sneaky, Duncan finds out that Geoff didn't stay loyal to the guys' Alliance by voting Bridgette off (even though she did leave without his help). Geoff was then seen saying good night to the rest of the boys outside the cabin, upside down, hanging from a tree. To Duncan, this disloyalty (as well as his all-around niceness) caused him to be voted off later in Trial by Tri-Armed Triathlon. In the next season, Geoff only made it to the second episode, when he and Bridgette were kicked off in Alien Resurr-eggtion. As Bridgette is clueless to why they were kicked off, Duncan tells them both that the remaining cast members used to like them, but now that they began to make out so much, the likeliness has gone. In the first two Aftermaths, Geoff constantly makes fun of Duncan during "That's Gonna Leave a Mark" segments and brings up his alleged relationship with Gwen in order to boost ratings, as well as to make it look like Duncan is cheating of Courtney.
Gwen is shown to have a love/hate relationship with Duncan throughout Total Drama Island: though they develop a camaraderie, there are times where Gwen wants him off the island, even choosing to try and eliminate him in Hide and Be Sneaky with the other girls, and not considering him one of the good people during her final rant in The Very Last Episode, Really! Even with these instances, during the second season, the contact between Gwen and Duncan has often been misinterpreted by the other contestants as a couple, causing tension and jealousy by their respective love partners.
The pair begins to have feelings for each other in Total Drama World Tour and share their first kiss after Duncan returns to the competition in I See London... They finally become a couple after they share another kiss in The EX-Files and after Courtney broke up with Duncan earlier in the episode, though their time together was short as Gwen was eliminated in the next episode. They are finally reunited after Duncan was eliminated again five episodes later.
However, their relationship is over two seasons later in Moon Madness when Gwen becomes jealous and angry that Duncan was constantly showing interest toward his ex-girlfriend Courtney, which results in Gwen dumping him. Duncan isn't heartbroken at being dump by her and would still attempt to warn Gwen about Mike not being what he seems. However, with both his exes being good friends now, Gwen refuses to heed his warning and occasionally mocks him.
Harold has a long history of conflict with Duncan which started in the first episode of the series. Throughout Total Drama Island, Duncan frequently picks on Harold by pulling several pranks on him. Harold eventually retaliates by rigging the elimination votes in Basic Straining and caused Courtney's elimination. Duncan eventually finds this out and their conflict becoming more and more intense in Total Drama Action. Being the final male members of their team however, the two of them are often paired with each other during challenges, frequently leading to their team's victory. Eventually, Duncan and Harold make a truce and temporarily end their conflict, but this is spoiled by Owen's interference and their conflict resumes. Their conflict is yet unresolved, but it uncertain where they currently stand due to having very little interaction after this event.
From the moment they met, Duncan immediately shows attraction towards Heather. He was very well known to sarcastically call Heather by pet names in Total Drama Island. while she calls him names based on his juvenile record in the next season. Despite this, Duncan, like most contestants, hated Heather's cruel nature at a time which he described to be worse than anything he did. For most of Total Drama Island, Duncan occasionally flirts with Heather though she always rebuffs him. After he is eliminated in Are We There Yeti?, Heather mocks him. In the next season, the two of them are more or less at better terms but are occasionally at odds with each other. Duncan's attraction for Heather also appears to have ended as he was disgusted when he is forced to kiss her during a challenge. Despite their conflict, Heather views Duncan as a great leader for their team as he is able to win many challenges for their team. However, she refuses to vote for either him or Beth during the finale, claiming that she deserve the money more than them. When Duncan returns in Total Drama World Tour, he occasionally teases Heather of her growing feelings for Alejandro.
Like everyone else, Duncan classifies Izzy's unusual behavior as pure insanity. However, he doesn't seem to have a conflict with her as the two are very similar in nature. In Search and Do Not Destroy, Duncan appears to be worried when he sees a snake wrapped around her head which bites her. Izzy cheers for Duncan in Hook, Line, and Screamer when he uncovers the identity of the fake killer behind the mask. In Wawanakwa Gone Wild!, Duncan finds Izzy's "sharp-shooting" tranquilizer skills to be very amusing when a tranquilizer dart is shot in Heather's butt. Because of being in a temporary alliance with Heather, he and Heather vote Izzy off the island later in the episode. In one of the promos for Total Drama, Drama, Drama, Drama Island, Izzy tells several campers a scary story that only Duncan enjoys.
In Mutiny on the Soundstage, Duncan calls Izzy a freak when he could not remember who Izzy was reincarnated as. Izzy was impressed with Duncan's break dancing skills in The Aftermath: IV. However, Izzy votes for her alter-ego (Explosivo) to win the million dollars although she does smile when Duncan is announced as the winner in his ending.
Both are placed on the same team in Total Drama All-Stars, and are seen to be on friendly terms in Heroes vs. Villains, after she warns him that she'll be running the team. He laughs when she points a pun on his name, after his key doesn't work. At the Campfire Ceremony, they give each other high-five after Chris announces their win. In Evil Dread, Duncan seems annoyed by Jo's bossy attitude, leading to being confused about whether to vote her out or Lightning. In Saving Private Leechball, Duncan was annoyed that Jo, Heather, and Alejandro kept on arguing throughout the challenge, knowing that they were actually trying to get him and his girlfriend to form an alliance with one of them. After their team lost, Duncan most probably voted for Jo as she cost them the challenge for shooting Scott with their own cannon.
Duncan and Justin had no connection with each other on Total Drama Island, as they were on separate teams. Duncan did, however, stare at him in Not So Happy Campers - Part 1 with the rest of the campers. In Total Drama Action, they seemed to get along with each other when they interacted in the guys' trailer though Duncan became annoyed when Justin refused to help him open the trailer door in The Chefshank Redemption because Justin was afraid that he'd ruin his manicure if he tried to help. In Super Hero-ld, Justin convinces Duncan and Harold to start a new guys' alliance in order to vote off one of the four remaining girls since they were outnumbered by them. Duncan and Harold agreed to join him.
However, any camaraderie Duncan and Justin had gone out the window in The Princess Pride. At the beginning of the episode, Duncan misleads Justin in the first part of the challenge as a prank, getting Justin hurt (which Duncan laughs at). Then, Justin spots Duncan cheating in the same challenge, but Chris does not believe him. After that, Justin begins to fall for Courtney, much to Duncan's jealousy and anger as he still has lingering feelings for Courtney. They continue to get into arguments over Courtney, mostly resulting from Duncan's jealousy that Courtney seems to be responding favorably to Justin's flirting. At the end of the episode, Justin is eliminated and Duncan, other than bidding him farewell in a sarcastic tone, doesn't seem to be upset with his elimination, along with the other contestants. In The Aftermath: IV, Chris showed that Duncan was nice to Justin once by fixing Justin's sleep mask while he slept. In order to get on Justin's good side, Duncan tells him that he still has his good looks during Justin's questions. However, Justin voted for Beth.
Like many of the other contestants, Duncan does not take Katie or Sadie seriously due to their bubbly and rather ditzy personalities. They both appear to be somewhat afraid of him, as they are shown to be hesitant when Courtney asks who is going to wake Duncan up during the episode, Dodgebrawl.
In The Sucky Outdoors, Duncan is one of the first to notice that Katie and Saide are missing from the team and asks everyone if they have seen "Tweedle-Dum and Tweedle-Idiot". Later, after Courtney suggests that the two might have been eaten by a bear, Duncan agrees with her and sarcastically says, "Darn shame". Sadie frowns when Duncan picks her and Harold as canoe partners in Up the Creek and in Who Can You Trust?, Sadie regards Duncan, along with the rest of the team as "marshmallow-eating freaks".
Although she dislikes him for being a mean and untrustworthy person early on in Total Drama Island, Leshawna is one of the first people who are aware that Duncan is more than just a tough guy. When the two are paired in Trial by Tri-Armed Triathlon, they easily get on each other nerves, frequently arguing on who should do what during the challenges. Eventually, Leshawna confronts Duncan that he is not as tough as he seems and reveals that she had an off-screen conversation with Courtney about the incident with DJ's bunny in Who Can You Trust? Duncan finally admits about his hidden soft side and the two put their differences aside in order to focus on the challenge. Despite this, tension rises between the two in Total Drama Action when they are put on the same team with Harold, and Leshawna has to frequently defend Harold from Duncan's bullying.
At the same time, Leshawna tries to form an alliance with Duncan and Harold but the two of them refuse. After Gwen's elimination, Leshawna begins to have a little respect for Duncan as his leadership skills allow them to win many challenges. Eventually, Duncan begins to hate Leshawna even more as not only she fake cried in order to get the reward in One Flu Over the Cuckoos all for herself, she also badmouthed everyone, mocking Duncan for being soft when he is around Courtney. Although he is mad, Duncan forgives her and let her stay in the competition a little longer. After the merge, Leshawna successfully convinces both Duncan and Harold to form an alliance with her but seeing how big of a threat Courtney is, Leshawna agrees to team up with Lindsay and Beth to eliminate Duncan in order to make Courtney mad. However, the plan fails when Leshawna herself was eliminated by the Guys' alliance and Courtney.
In Evil Dread, Duncan states that he opted to vote for Lightning or Jo, finding both of them annoying, but couldn't decide on who. It is implied that he finally decided to vote off Lightning as he is the reason their team lost the challenge.
For most of the series, Duncan and Lindsay appears to have a minor conflict although this is mostly because of Lindsay transferring her hatred towards his first girlfriend to Duncan. In Not So Happy Campers - Part 1, Duncan is briefly seen with his arm around Lindsay. While she appears to be scared, she doesn't say anything. In X-Treme Torture, Duncan and Lindsay were paired up in the final challenge. Duncan was furious that he failed to make Lindsay lose the challenge which leads to a Screaming Gophers victory. He is so angered by this he nearly attacks Chris, to force him in giving his marshmallow. In Brunch of Disgustingness, Chris explains that the challenge will be a regular "Battle of the Sexes”. Duncan gives emphasis to the word "sexes" towards Lindsay by winking at her. She responded by sticking her tongue out at him.
In That's Off the Chain!, Duncan was seen to be annoyed at DJ and Owen talking to Lindsay. When Duncan needs to ride Lindsay's bike, he disapproves of it due to its girly nature but ultimately does it and even compliments her for making a fast bike. Duncan backed up Lindsay when she discovers Heather's betrayal, saying that it was "cold". He seemed arguably sad at the Dock of Shame this episode, and smiled a tad when Lindsay said goodbye to him. However, during Haute Camp-ture, Lindsay calls him cruel and claims to hate his treatment towards deer and trees.Lindsay joined Beth and Leshawna to voted Duncan off in Super Hero-ld, but they failed due to The Second Guys Alliance, and Leshawna was eliminated instead. Also, in The Princess Pride, Duncan makes fun of Lindsay's large feet, calling Lindsay "Big Foot", which upset her. He teases her again during the first challenge and this distraction causes Lindsay to fail the challenge. In Get a Clue, Lindsay handcuffs Duncan when she, Harold and Beth think he is the murderer. However, Lindsay eventually finds out that Duncan was innocent and apologized to him for accusing him. She then makes up for her mistake and brings him to the movies with her. Although they found it hard to talk at all due to their obvious differences, they both took pleasure in torturing Courtney and making her jealous.
In Rock n' Rule, Duncan admits that he finds their date the previous night terrible and is even more annoyed when she started singing horribly. Lindsay devised a plan to vote off Duncan along with Beth, Harold, and Owen. Unfortunately, she got distracted by Beth when she looked at her and accidentally voted herself off, leaving Duncan safe. When the video shows Lindsay voting for herself after it was revealed that she got sent home, Duncan laughs rudely at her mistake, and does not seem upset.
According to Duncan, he knew Mike, who was known as Mal at the time, from juvenile hall when he was first incarcerated. Knowing how dangerous Mal is, Duncan stays away from him. Because of this, Mike does not recognize Duncan when they met in Total Drama All-Stars. After Duncan was transferred to the same team with Mike, Duncan initially doesn't remember Mike, but over time, he begins to recognize Mike's voice and finally remembers that he is Mal after listening to his whistling. For the next few episodes, Duncan tries to tell the other contestants, but his efforts are mostly futile, with only Zoey believing him.
This conflict first begins in Not So Happy Campers - Part 1, when Duncan makes a remark about Noah's mother, prompting Noah to sarcastically remark on Duncan's piercings. Duncan then grabs Noah's lip and threatens to pierce it, to which Noah calmly requests that he let go. Duncan obliges and Noah thanks him sarcastically. During Total Drama, Drama, Drama, Drama Island, Duncan is abandoned by Courtney after the former sprains his ankle. Noah then walks up to him and mocks Duncan on how his girlfriend abandons him and how he just became "less of a man". An enraged Duncan pulls Noah pants off in retaliation for mocking him.
In The Aftermath: IV when it is revealed that Duncan wins the money, Noah is seen with an unsatisfied look on his face. In Beth's ending, he is seen cheering with Beth. Duncan, along with Gwen and Cody, laugh at Noah when they found out he is Chris's assistant in Celebrity Manhunt's Total Drama Action Reunion Special.
In I See London..., Duncan votes off Noah as soon as he returned to the competition. In Sweden Sour, Duncan uses Noah's absence as a strategy to get Owen on his side. Duncan tells Owen that they should honor Noah's parting words by allying together against Alejandro. He later asks Owen, "What would Noah do?" in order to get Owen to fully turn against Alejandro.
Along with Heather, Duncan is one of the main people to criticize Owen over his weight and/or consumption habits. This includes Duncan forcing Owen to join the Guys' Alliance by dangling him over a short cliff. Despite this, there are many instances where they get along well. Duncan would go on to support Owen in the finale of Total Drama Island while Owen does the same in Total Drama Action. When Duncan returns to the competition in Total Drama World Tour, Owen is one of the few contestants remaining who isn't mad at Duncan for kissing Gwen. Duncan would later warn Owen not to trust Alejandro, using Noah's last words to encourage him, trying his best to get on Owen's good side. Duncan admits that he misses him after Owen is voted off, as he feels he lost a valuable ally.
Sam and the rest of the team threw a surprise party for Duncan in Food Fright after he was added to the team in the previous episode. When Sam suggests that they sing the "Welcome Song", Duncan strongly disagrees. During the challenge, Duncan is seen cheering for Sam though he immediately denies it.
Through their limited interactions in Total Drama All-Stars, Duncan and Scott appear to get along.
In Heroes vs. Villains, Duncan and Lightning are attempting to talk Scott into jumping off the cliff to get the key for the McLean Spa Hotel. Lightning manages to pry Scott off the rock he was holding to, but ended up pushing the Robot off instead. In Evil Dread, Duncan and Scott are seen sitting next to each other in the McLean Spa Hotel, toasting to their villain status. In Saving Private Leechball, Duncan reveals that he has a liking to Scott, finding his clumsiness amusing. However, during the challenge they are seen arguing over who gets the cannon. In Moon Madness, Duncan believes Courtney is using Scott to make him jealous, and pretends to not be jealous or bothered.
In No One Eggspects The Spanish Opposition, Duncan laughs at Scott when he falls to the ground in an attempt to appear villainous, but still ends up helping him up, causing Scott to thank him, much to Duncan's dismay.
In You Regatta Be Kidding Me, Duncan and Scott join Cameron and Zoey's team after Mal's mischief leaves them without another way to participate in the challenge. The former later goes along with Cameron's plan to use Scott as bait for Fang, in order to give their raft a "motor". Duncan even calls the shark to them, laughing as he does. Scott yells back angrily at Duncan in response, yelling that it's not funny for him.
While the two of them have little interaction early on in Total Drama World Tour, Sierra apparently dislikes him, though this is mainly because of Cody hating Duncan as well. In Celebrity Manhunt's Total Drama Action Reunion Special, Duncan and Courtney coldly respond to Sierra's friendly greeting when she attempts to interview them. While she sees Duncan's relationship with Courtney as the series' favorite couple, Sierra also supports his relationship with Gwen, even before the two become an official couple, believing that the two had feelings for each other since season one.
In Greece's Pieces, Sierra is thrilled when Cody punched Duncan and was talking about how Cody's fans would go crazy in excitement. In African Lying Safari, she refuses to make an alliance with Duncan and in an exclusive clip from the episode, Duncan mentions he is glad to be away from Sierra. Sierra also mentions her belief that Duncan has had feelings for Gwen since season one.
In Food Fright, the two become teammates after Duncan switches teams with Courtney. Sierra and the others host a surprise welcome party for him in the next episode. Excited that Duncan was now on the Heroic Hamsters, Sierra quickly goes to get her smartphone for a photo, only to find out someone broke it. In No One Eggspects The Spanish Opposition, Sierra offers to work with Duncan to search for eggs if he allowed her to call him Cody. However, Duncan turns down her offer, as he was trying to assert his villainous status at the time, to which Sierra rolls her eyes and walks off. In Suckers Punched, Duncan finds her Gwuncan blog amusing and tells her to continue making them before she took the Flush of Shame.
These two didn't have much any conflict with each other in the first season, and even a friendship after (and possibly before) the merge. However, Trent's jealousy and believing that Duncan is stealing Gwen from him, drove them to become partial enemies during the early episodes of the second season. However, by the third season, the conflict seems to be resolved and Trent seems to accept the fact Duncan is dating Gwen.
While the two of them appear to be friends in Camp TV, Duncan and Tyler don't get along in the actual series. In Not So Happy Campers - Part 1, Tyler is shown to be against sharing a cabin with Duncan, and takes credit for Duncan's extermination of a cockroach, claiming he could do that as well to impress Lindsay. Duncan then mutters that girls like Lindsay "always go for the jocks". Also, in Not So Happy Campers - Part 2, Duncan and Tyler are seen fighting over a hammer. Later in the episode, Duncan defends Tyler when Courtney suggests the team to vote him off instead of her saying that at least he jumped. In Dodgebrawl, Tyler is shown to fear Duncan when the latter tells him he better not be woken up, and he gulps and has a look of fear. In Phobia Factor, even though Tyler gives support to Duncan while he tries to overcome his fear, Duncan mocks Tyler's fear of chickens when he was leaving for the loser boat. This, however, does not stop Tyler from cheering for Duncan when he is declared the winner of Total Drama Action in his ending of The Aftermath IV.
In Greece's Pieces, Duncan angrily says in the confessional that he knows that Tyler saw him and Gwen kissing in the previous episode and threatens that Tyler should know better. He glares at him in economy class, knowing that Tyler is considering saying something about the incident. After being persuaded by Alejandro, Tyler tells everyone about Duncan's secret, he is disappointed and frightened when Duncan does not get eliminated. In The EX-Files, after Duncan is recovering from being kicked in the groin by Courtney, Tyler complains about Duncan to Alejandro and Owen, calling him a jerk and that saying that he'd never cheat on Lindsay the way Duncan cheated on Courtney, even adding that Duncan deserved two kicks to the groin instead of just one for what he has done. However, Tyler admires Duncan, as he is able to win the hearts of two hotties. After witnessing his teammates being attacked by aliens, Duncan punches Tyler's face, effectively destroying the alien that latched onto his face. Duncan is later partially responsible for getting Tyler eliminated, where he and Alejandro have plotted together to vote him off.
After being transferred to the Heroic Hamsters, Duncan at first distrusts his new teammates but eventually warmed up to Zoey. Unlike most people, Zoey knows that despite Duncan's criminal history and his "tough guy talk", he is actually a nice person. She finds this trait of him adorable, not realizing that this greatly bothers Duncan, who is desperately trying to maintain his "bad boy" image. When Duncan discovers an old foe from juvie is on his team, Zoey is the first person Duncan warned. Although she has some doubts, Zoey trusts Duncan, becoming the only person to take Duncan's words seriously as everyone else either ignores him or mocks him when he tries to advise them.
|Interactions with||Everyone | Alejandro | Beth | Chef Hatchet | Chris | Courtney | DJ and Geoff | Gwen | Harold | Heather | Leshawna | Mike | Owen | Trent | Zoey|
|Other content||Guys' alliances | Scruffy|
|Hosts||Chef | Chris|
|First generation||Alejandro | Beth | Bridgette | Courtney | DJ | Duncan | Ezekiel | Geoff | Gwen | Harold | Heather | Izzy | Justin | Leshawna | Lindsay | Owen|
|Second generation||Cameron | Jo | Scott | Zoey|
|Third generation||Dave | Jasmine | Shawn | Sky | Sugar|