|“||All for quad, and quad for all!||”|
— The Quad Code
The quads usually hangout together most of the time. They all used to share the same bedroom until Dawn moved out in Dawn Moves Out after realizing that soon her body will be undergoing changes.
The Quad Members
Listed in the order of birth revealed in Doggy Door Afternoon.
- Dawn Harper - the only girl in the quad. She believes she's the normal one compared to her brothers. She comes off as a bit controlling in her attempt to be the leader of the quad. She's great at sports.
- Ricky Harper - the smartest one of the quad. He's often disappointed by his siblings because they never seem to take anything seriously. He also competes with Dawn to be the leader of the quad.
- Dicky Harper - the "cool" member of the quad. He never puts effort in anything and never really takes anything seriously. He also has trouble understanding simple things.
- Nicky Harper - the quiet one in the quad. He tries to stay away from his siblings' shenanigans but always gets caught in the middle. He's a great chef who values his work.
Both Dawn and Ricky think that they're the leaders of the quads and often end up arguing about who is the leader. Dawn makes most of the decisions for the quad followed by Ricky. Dawn usually wins most of the times either because she has the best idea or by intimidating the other quads. In Doggy Door Afternoon, Dawn knew that if she suggested to be in charge while parents are out, they would end-up fighting with Ricky and the parents would refuse to leave them alone. So, she nominated Ricky to be in charge but after the parents left she told Ricky that she's in charge and took over by force.
Dicky and Nicky usually side with Dawn against Ricky because Ricky tends to think that he's smarter, more mature and better than everyone else. They also find Ricky to be too nerdy and serious while Dawn is more fun and care-free. For example in Quaddy-Shack, Ricky turned against his siblings for being "classless garbage eaters" who never take anything seriously. When Dawn is tired of Ricky being right all the time in She Blinded Him with Science (Bob), she leads Dicky and Nicky to help her in schemes to trick Ricky into thinking superstitions are real.
The Harper Quads have a bad reputation in the area because of their many shenanigans. In M.D. Day, it is revealed that they're banned from most hospitals / doctors in the area. In New Kid on the Block, they try to hangout with Syd but she reveals that she can't hangout with them because of their bad reputation. They ask their mother if they're really bad kids and she lists them all the bad things they've been involved in. They conclude that they're not bad - they're just victims of circumstances.
In Quadshank Redemption, the other "bad kids" at detention accuse the quads of ruining up things for everyone else because they're selfish. They list several instances where other people had to suffer because of a mess caused by the quads - including in Nicky, Ricky, Dicky & Sicky when the quads went to a field trip while sick and got everyone else sick. In Quad for Teacher, the quads face similar accusations by their classmates during P.E. for always messing up things. Trey says that he has a list of things the quads have messed up with.
When the quads get their gym coach injured in Quad for Teacher, the other students blame the quads for ruining everything. Trey says he has a list of all the things the quads ruined after promising to fix.
During a committee meeting for the Edgewood School Class of 2017 graduation stunt in Cementing the Quads' Legacy, the Harper Quads fail to agree with the rest of the committee about the type of stunt to pull. When things get out of control, Natlee appoints the quads to be in charge of the "super secret committee" to plan the class stunt. They later realize that Natlee had actually tricked and kicked them out so the rest of the committee can continue planning the stunt. Natlee, Mae and the rest of the class agree that the Harpers always "quad things up" whenever they're involved with anything because they never stop arguing.
The quads come to a realization that they're leaving bad legacy and reputation behind and they must fix it.
The Harper Quads are very competitive - especially Dawn and Ricky.
- In Harpers for President, the quads competed against each other for class president. They election result was a four-way tie but Ricky tricked the rest into giving it up since they weren't willing to do much work.
- In The Quad-Test, the quads compete for who can go the longest time without their baby security items.
- In Unhappy Campers, Dawn "dated" all of her brothers after they agreed to pretend that they are not related at the camp.
- In Three Men and a Mae B., all of the boys had a crush on Mae Valentine; Dawn had to interfere and stop them.
- Dawn told her brothers that she had a crush on Mack.
- In Ye Olde Hand Holde, the quads competed to see who will hold their date's hand first to prove that they're more mature. Dawn went with Mack while the boys asked out girls they haven't really hangout with. Needless to say, all the quads ended up embarrassing themselves, with no real winner.
Dawn vs Her Brothers
Being the only girl in the quad, it means that Dawn has to deal with her 3 brothers, whom she finds annoying at times.
- In I Want Candace, Dawn stops speaking to her brothers after they interfere with her radio call when she was just about to win a ticket to meet her idol, Candace Parker.
- In Diary of an Angry Quad, Dawn is frustrated when she realizes that her brothers keep going into her room, and read her diary. So she fires back by writing fake diary entries to torture them.
- In Ballet and the Beasts, Dawn is tired of hanging out with her brothers all the time, so she tries to join other activities that don't involve the boys.
- In One Quadzy Summer, Dawn gets a summer job at the Boulderly Hills Country Club and says she's a "go-getter" while her lazy brothers are "no-getters." The boys find their way into the BHCC and manage to make life difficult for Dawn.
- The Harper Quads feel threatened by The Kramdens Quads.
- Mae Valentine considers herself to be the "fifth quad" as shown in "Quadsled".
- Dawn is four seconds older than Ricky.
- Nicky was going to be a girl named Nikki and Dawn was going to be named a boy named Don. Also, the Harpers were going to be the Haylees.
- Tom was going to name Ricky “Gary” but he couldn’t think of three names that rhyme. Later, Nicky, Dawn, and Dicky suggested “Larry,” “Carrie,” and “Harry.”