Did Grace win the game and survive the night on her own or was Mr. La Bail subtly manipulating the events to make sure that the Le Domas Family will lose so he can break their contract and wipe them all out?
It is also ambiguous whether the deaths of the maids counted as the sacrifice. The family decides not to risk it but it's possible that the family all died not because they didn't go through with the sacrifice, but because they still tried to kill Grace past the set time, thus breaking the rules.
Was Daniel's dickish behavior at the start (implying the family thinks Grace might be a gold digger, hitting on Grace as she mentioned, suggesting she back out) simply him being an apathetic drunk, or was he trying to drive Grace away to prevent the wedding and the hunt in the first place?
Daniel's actions in the first two acts hang entirely on this trope. He is obviously an unwilling participant, but how much of a participant depends on your interpretation. When he gives Grace a head start before calling the rest of the family is he doing the bare minimum or is he hoping the calling them to the room he knows Grace is running away from will give her more time? Was he really just buying time for Tony to knock out Daniel, or was he just avoiding revealing his true sympathies to his father? When he knocks Grace out in the end, is it just because the father is watching? Or to gather all the family and poison them all? Was the MEH moments there really what pushed him to finally take a side, or did he plan to poison the chalice earlier, if not from the very beginning?
In the end, does Helene fly into a homicidal rage because Grace’s survival means they failed to carry out the ritual or is she resentful that Grace managed to survive the game when her own husband did not? Or was it simple trying to prevent Grace from reporting them to the police for attempting to kill her?
Did Alex betray Grace out of cowardice, because she was breaking up with him, because she killed his mother or because he thought she killed his brother?
Speaking of Alex, was he honest when he said that he didn't really believe they would have hunted down Grace? Daniel hid him in their childhood so that he would not have seen the game playing out, but later we learned that he saw (or, at least, claimed to see) Mr. Le Bail as a child, and mentions the family continuous goat sacrifice as a reason he left. He also says that he knew Grace would have left him, which would imply he was well aware of the reality of the threat, and just hoping not to have to face it.
Would Alex have been spared if Grace forgave him? He is the last of his family to die, has enough time to beg Grace to spare him, and only explodes after she throws her ring at him. Was Mr. Le Bail giving Grace the chance to spare him as reward for winning his game?
Catharsis Factor: Admit it, you cheered when the Le Domas family members started exploding one by one at the end. Especially Alex, who willingly betrayed Grace.
Draco in Leather Pants: Daniel could be classified as such. He does eventually help Grace in the end, but spends most of the movie disgusted but passively going along with his family, as much as he clearly doesn’t want to.
Ensemble Dark Horse: Daniel, for being the Only Sane Man in the family and the one to die trying to save Grace, whereas even her own husband eventually turns against her. Being played by Adam Brody also helps his popularity.
Grace survived the night and all of the Le Domases are dead, however she’ll likely be scarred for life because of what she experienced along with the legal ramifications of what happened. Fire is actually very inefficient at destroying forensic evidence, so a good forensics investigation will corroborate her story, note Fingerprint analysis will likely prove that her prints aren't on the murder weapons for the maids meaning someone else held those weapons and killed them, blood spatter analysis of the dining room table will confirm that each family member literally exploded without apparent external cause, her blood tox screen may show traces of the tranquilizer in her system, Charles's body in the goat pit that's older than Grace is, etc. but that can take a long time, and she'll definitely be the prime suspect and be under intense scrutiny. It's going to be a long and traumatic legal ordeal for her going forward, on top of having to trying to get some mobility back in her left hand.
Then again, the see-through hole in her left hand is a pretty clear indication that she was in fact attacked, and it's pretty easy to argue that it's unlikely for a single woman to slaughter a whole family. If you factor in the call to the car's security (which has her screaming they are trying to kill her and asking for the police long before the family's deaths) and the pit full of corpses in the family backyard (some of which were already reduced to skeletons by the time of the wedding, and since one of them was implied to be Helene's husband some will date to unsolved murders when Grace was still a child) it won't be too hard to prove that the family was messed up and Grace was a lucky survivor. And considering that the bodies exploded, good luck convincing any jury Grace was able to do that.
Fandom-Specific Plot: Fan writers are fond of trapping Grace or Daniel in a "Groundhog Day" Loop repeating on the day of the wedding and the Le Domases’ deadly game. Armed with foreknowledge of the game, Grace will be forced to try to break the loops by winning the game in a different way, calling off the wedding, or getting other characters such as Daniel also out of the game alive.
Friendly Fandoms: Fans of this film usually like Knives Out and vice versa, what with their ripping takedowns of the wealthy, smart and scrappy leading ladies, and big fancy houses. A few fans have even liked to imagine Grace and Marta meeting and, due to their similar personalities, becoming good friends.
Alex. He tries to get out of the family or at least be better than them, only to ultimately participate in the game anyway and die for it.
Emilie's kids. Her poor kids. Yes, they belong to an incredibly fucked-up family, and it's really hard to blame Grace for punching Georgie after he shoots her hand, after all of the trauma they've collectively put her through. Still, they're kids who are plainly being brainwashed into thinking violence and murder are fun games. They genuinely can't tell wrong from right, and the fact that elders within the clan are repeatedly shown praising children for participating in rituals is... painful to see, to say the least.
Aunt Helene had to watch her husband be betrayed by Daniel and then murdered by the family 30 years ago, making her hostile behaviour against the rest of the family and newcomer Grace at least understandable as she lost a loved one when no one else did.
Charity. She's a deeply unpleasant woman who openly only married Daniel for his wealth and will do anything to keep it, even if it means killing an innocent woman. But she apparently came from a very bad and impoverished background that she is desperate not to go back to and her final words are her desperately begging to be spared and to just go home, making it hard not to pity her.
Emilie, despite partaking in the hunt, is shown to be genuinely friendly, if a bit ditzy, and eagerly tells Grace upon meeting her that she's thrilled they'll be sisters. Although her parenting is naturally warped, she is shown to genuinely love her sons, and in a moment of unnatural seriousness for her, tells Daniel that her children shouldn't have to die. Also, her compulsive drug use throughout the hunt could possibly be interpreted as her own method of coping with the inhumanity of the situation. Her final act of grabbing her sons and getting them away in a futile attempt to escape Le Bail's wrath is sad enough to procure some sympathy for her.
Love to Hate: While Grace is a sweetheart, the Le Domases are surprisingly likeable for slasher villains due to their incompetence, banter and dysfunctionality making them Laughably Evil and strangely sympathetic.
Magnificent Bastard: Mr. Le Bail is the rarely-seen, supernatural benefactor of the Le Domas clan, having manipulated their ancestor into a Faustian deal that involves the Le Domas family playing a game in Le Bail's name every time a new family member is added to their ranks in exchange for wealth and prosperity for them all. Le Bail randomly chooses the game "Hide and Seek" every few years, a game that involves the Le Domas clan hunting down the newest member of their family and sacrificing them to Le Bail, under threat of all the Le Domases being wiped out if they fail or refuse to play. When the latest sacrifice, Grace, fights back and survives the time limit of the game, Le Bail follows through on his terms and massacres the hateable Le Domases while ironically playing their own Hide and Seek music back on them, before materializing before Grace to show genuine respect at her outwitting his pawns and surviving the night.
Moe: There's a reason Samara Weaving was given great acclaim for her performance as Grace. Her very bright blue eyes, her sweet smile, and her adorable nervousness around Alex's family and genuinely kind personality make her seem like a true live-action Disney princess. It makes it all the more tragic with all the trauma she endures throughout the night, and consequently all more cathartic when she sheds this innocence and fights back, beating Charity and Tony, and killing Becky and Stevens. Especially when she disowns Alex for betraying her and lets him die.
Alex crossed it when he decided to sacrifice his own wife in order to save his own life. The worst part is that he initially tried to genuinely save his wife but after witnessing his brother's death and seeing the aftermath of Grace beating his mother to death, he believed that there was nothing left except to go along with the ritual.
Aunt Helene crossed it when she decided to kill Grace even though nothing happened after the ritual failed to occur before sunrise. This is possibly the reason why she and everyone else in the family died right afterwards.
While he took a while to act on it, Daniel's reaction to Georgie explaining that he tried to shoot Grace because everyone else was doing it and Emilie praising the boy for his actions may be what inspired him to turn on his family to help Grace, reasoning that a family that produces a seven-year-old child who has no problem trying to kill someone has crossed so many lines that they may not deserve to live.
Paranoia Fuel: Be careful what family you marry into. You never know if you'll end up spending your wedding night with them standing over you with daggers chanting "hail Satan".
Shocking Moments: The end seems to avert All Myths Are True when Grace runs out the clock and survives to dawn and nothing happens to the family. Helene announces her intent to still kill Grace... and she suddenly explodes.
Spiritual Successor: To You're Next. The films were released eight years apart, but both center around inheritance issues, feature large and wealthy families as the main characters, and have an intelligent, resourceful, and determined Action/Final Girl fighting back largely single-handedly against a large group of killers. Both films also feature the Final Girls suffering a betrayal at the hands of their significant others, resulting in said Final Girls killing them.
Grace. Her backstory implies that she had a healthy but unfulfilling upbringing since she didn't have a family, and was bounced around foster homes where her guardians meant well and cared for her but they knew they wouldn't be able to do so long term. She looks forward to inheriting a family through her marriage to Alex, but several of them treat her with disdain. The night of her wedding, she's hunted down by those same in-laws who want to sacrifice her to Satan. After she accumulates numerous injuries trying to survive, Daniel tries to help her escape only to be shot dead, and even her husband turns against her. She only barely survives due to the Le Domases running out of time. And there's no indication that she emerged from this trauma with her sanity intact.
Daniel. When he was a child, he was brainwashed by his family so strongly that he betrayed Helene's husband Charles, an act that traumatized him permanently. This only worsens in his adult life when his parents openly disfavor him, and he marries an unloving Gold Digger. The only family member who he cares about and who cares about him is Alex, the little brother he spent his life trying to protect from the family nonsense. He eventually saves Grace's life only to be shot dead by his own Gold Digger wife. Even worse, Alex ends up betraying Grace, rendering his death almost completely meaningless.
