In The Rules of Survival, Matthew, Callie, and Emmy live through two extremes of family life. At the beginning, when they live with Nikki, their family life is both terrifying and unpredictable—they're always worried about setting Nikki off and getting hurt or abandoned for days on end. It's super rough.
When Nikki loses custody, though, the kids are able to cobble together a real and safe family—one where they have adults looking out for them. It may not look like a "normal" family, since Callie lives with Ben while Emmy and Matthew live with Aunt Bobbie, but it works for them.
Matthew starts calling his mother Nikki instead of Mom as a way to symbolically disown her as a member of his family.
Even though Nikki raises the kids for many years, Matthew, Callie, and Emmy have all decided to remove her from their family tree and to call Aunt Bobbie their mother instead because she provides real maternal support.
In The Rules of Survival, Nikki is constantly surprising her kids—and not in a good way. She doesn't cut their sandwiches into cute shapes, or take them on road trips to Disneyland… No, Nikki is constantly keeping her children on their toes by absolutely terrifying them with her erratic behavior. Matthew, Callie, and Emmy grow up without the sense of safety or security, even when they are at home. It's exhausting and no way to live, especially for a bunch of kids. This fear drives Matthew to seek help and to change their living situation, though—it forces him to act.
Although fear can be useful in alerting you to danger, the kind of constant fear that the Walsh kids live with isn't useful. Instead, it starts to destroy them and their will to live.
Matthew is so drawn to Murdoch from the very beginning because he doesn't act like he's afraid of abusive parents—he stands up to them without fear of violent repercussions.
There are quite a few broken windows, bruises, and car accidents going on in The Rules of Survival, thanks to Nikki's unpredictable and violent presence. Nikki is constantly reacting violently to perceived slights from her kids—once she even holds up a knife to Matthew's throat because he takes an Oreo without asking first. Talk about an overreaction, right? She also has someone beat up Murdoch because he dumps her, and eventually causes Julie Lindemann's car crash and paralysis.
Nikki is dangerous, erratic, and up to no good. She's definitely not someone who should be in charge of three children.
Nikki hurts the children physically when she is angry with them, but the real damage is in the emotional abuse that she rains down on them constantly.
In living so long with Nikki, Matthew begins to internalize some of her violent behaviors and tendencies. This is why, at the end, the only solution that he can think of is to kill her.
Even though Nikki leaves for days on end and has her kids fend for themselves, they don't exactly feel free. In fact, Matthew claims that he feels more trapped than ever in The Rules of Survival, because they're stuck in such a dysfunctional family situation and are all too young to get out. Even when Nikki hits him and tells him to get out, he realizes that he cannot leave—he can't just walk out, leave his siblings behind, and find someplace else to live. It is only when Nikki loses custody that the kids feel really free to be themselves, instead of constantly in survival mode.
Even though Nikki often leaves the children alone for days on end, they are not really free to do as they please. They are still chained to her, even when they are physically apart.
The children can only experience real freedom when Nikki is experiencing imprisonment. It is only when she is in jail that they can relax and be themselves.
For much of The Rules of Survival, Matthew and his siblings are convinced that life just isn't fair. After all, they're stuck with a violent and emotionally-abusive mother who lashes out at them for no reason, and things don't seem to change, even when Matthew takes the initiative and talks to his dad about their situation. It looks like they're stuck here forever and that Nikki is just going to continue getting away with her bad behavior. With Murdoch, Ben, and Aunt Bobbie's help, though, they eventually get justice when Nikki loses custody, and things turn out okay after all.
Matthew expects that the state of Massachusetts will be the entity to bring Nikki down, but in the end, the kids win because of the hard work of three individual adults—Murdoch, Aunt Bobbie, and Ben.
Even though Murdoch understands why Matthew feels like killing his mother would be an act of justice, he stops him because he does not want Matthew to have to live with that kind of guilt and darkness.
The tough thing about living with Nikki in The Rules of Survival is that as the sole adult, she has all the power—even though she's not exactly qualified to be the head of her family. Matthew, Callie, and Emmy may actively hate Nikki sometimes, but they still have to listen to her and live under her oppressive rules because otherwise, they'll get hurt.
When Nikki loses custody, though, the kids realize that she doesn't have any sort of power over them anymore. She can scream and wreak havoc on the house all she wants, but she cannot tell them what to do any longer. They finally get to live their own lives and make their own decisions.
Nikki is infuriated by Murdoch because he doesn't fall under her powers of seduction and control.
Even though Emmy is the youngest of the Walsh kids, she is the only one who is willing to stand up to Nikki on a regular basis and question her power. This is due to the fact that Emmy has not suffered as much as her siblings, and because of this, her fighting spirit remains intact.
If there is one important lesson to take away from The Rules of Survival, it's that you should never give up. Matthew, Callie, and Emmy come close to giving up a million times, and it's tempting for them to resign themselves to just trying to survive. But through hard work and perseverance—and with a little help from Aunt Bobbie, Murdoch, and Ben—they manage to turn their situation around. They rally together and refuse to give up when it comes to trying to take custody away from Nikki, and their works pays off when they eventually end up doing just that.
Callie has inherited her mother's perseverance, but uses it for good instead of bad. Whereas Nikki destroys those around her untiringly, Callie uses her perseverance to continue working hard and to succeed in life.
Matthew is afraid that all of the adults in his life are going to give up on them, but Murdoch infuses Aunt Bobbie and Ben with a sense of purpose and leads them to work tirelessly toward freeing the kids from Nikki's clutches.
Even though the Walsh kids have lived in the same house all their lives in The Rules of Survival, it doesn't feel like a real home to them. Homes are supposed to be safe and comfortable, and Nikki makes sure that they feel constantly on-edge and endangered when they're at "home" with her.
It isn't until they move in with their new guardians that the kids start to feel comfortable and truly at home. Even though Callie, Matthew, and Emmy are in separate households, they feel more comfortable and like a part of a real family than they ever have before. Even Aunt Bobbie's snoring can't get Matthew down—he'd take that noise over all of Nikki's crazed screaming any day.
In this book, home isn't where the heart is—it's where the heart is safe.
Matthew fails to run away not because he'll miss home, but because he needs to take his siblings with them if he goes anywhere. To him, home is wherever his real family is.
In The Rules of Survival, Nikki isn't exactly a stellar mom or role model. She is constantly lying in order to get her own way, and the kids watch her trick people time and again. When she starts dating Murdoch, she's able to hide her craziness for a while, but eventually she cracks up. After Murdoch dumps her, though, Nikki takes her lying and scheming ways to a whole other level, even getting her new dude to beat her up so she can claim Murdoch attacked her. No matter the consequences, Nikki is set on lying and cheating her way through life.
Nikki gets away with so much because she is an excellent liar when it comes to men. She uses her skills of deception to seduce men and get them to believe her far-fetched sob stories.
Matthew decides to call out Nikki on lying about Murdoch attacking her, not because he worries about Murdoch, but because another adult—Aunt Bobbie—finally believes him.
The adults in The Rules of Survival are all challenged to make serious choices about their role in keeping the Walsh kids safe. Are they going to rise to the responsibility, or are they going to run away? Nikki obviously chooses the latter. She's an awful mom when she is around, and in the end she just runs away and never comes back.
Murdoch, however, has a tougher decision—he's not even related to these kids, and yet he's the one who swoops in to save them because he recognizes that they're in trouble. In doing so, he manages to bring Ben and Aunt Bobbie around, and turns them all into a small army of people looking out for the kids' best interests.
Although Ben has been a pretty deadbeat father figure for most of the kids' lives, when he decides to start taking care of them, he really commits and turns his life—and his priorities—around.
Even though Matthew has already made the decision to kill his mother, Murdoch manages to talk him out of it because he has made the same decision in his life—and he knows what it leads to.