The hero of Bastion. Woke up late one day to find everything had been shattered after the Calamity rocked the world.
- Alternate Character Interpretation: In-universe. During a Mushroom Samba flashback, the narrator paints the Kid as a villain in everything he does, no matter how harmless.
- Badass Adorable: Despite his (presumably) young age and nickname "The Kid", he is an extremely Badass One-Man Army in battle.
- Badass Normal: He's just an ordinary human who wields weapons, and yet has faces no trouble defeating anyone (and anything) he fights against with ease.
- Dark and Troubled Past: He went to fight to earn money for his mother, but when he returns, his mother has passed away and the money is gone.
- Death Seeker: The Rippling Walls were a terrible place to work, but the Kid struggled for his mother. And then she died before he even came back. He then applied for ANOTHER tour to the Walls. It should be noted that he's the first person to ever do so.
- Determinator: Monument's broken? Get the shards. Broken again? Get more.
- Heroic Mime: Occasionally people react to what he says, but you never hear him. Even at the point after Rucks's narration is done, you never hear his voice, although there is always a description of what he is asking people when he shows them items.
- Heroic Self-Deprecation: During the Mushroom Samba in Jawson Bog, the Kid turns out to feel very guilty of the things he's done, with the narration calling him a thief and a murderer.
- Multi-Melee Master/Multi-Ranged Master: The can switch between several weapons, and he's a master of all of them. Justified, as he toured the Rippling Walls TWICE.
- Talking in Your Sleep: According to Rucks' narration in the Kid's Who Knows Where, he does this.
- No Name Given/Only Known by Their Nickname: He's The Kid.
- One-Man Army: Solos all the monsters inhabiting what's left of the City and the Wilds, as well as what's left of the Ura army.
- Parental Abandonment: His father is missing and his mother died during his first tour of duty on the Walls.
- Scarf of Asskicking
- Vague Age: His exact age is never given, and although he is referred to as a kid, he seems to at least be in his late teens or a young adult.
The first survivor of the Calamity that the Kid finds. He serves as the narrator for the game.
- Mission Control: He's the one that sends the Kid out to look for shards.
- Multiple-Choice Past: Just what does Rucks do? He was, for certain, a Mancer.
- My Greatest Failure: He belonged to the guild that designed the Calamity weapon; though he wasn't the one who set it off, he clearly feels responsibility for the Calamity. It's why he's so obsessed with fixing the Bastion to undo everything.
- Nay-Theist: Regularly snarks about the gods (especially when the Pantheon is involved.)
- Reasonable Authority Figure: While Rucks is very strongly inclined towards using the Bastion, he freely admits that he has no idea if it will work or not, and ultimately leaves the choice up to the Kid.
- Retired Badass: It's heavily implied that Rucks was once a member of the Triggers, an elite squad of Caelondian riflemen. Also, it's all but confirmed that he was quite the renaissance man his youth.
- World Half Empty: His view on the Calamity. He wants to reset the world in his ending.
A man that the Kid finds in the Hanging Gardens. He is an Ura ambassador to Caelondia.
- Berserk Button: He really flips out when he finds out that the Cael Mancers designed the Calamity weapon that destroyed Caelondia, killed the woman he loved, and blew the Tazal Terminals sky high. Especially notable given the fact that, before it happened, he was a voice of peace and reason for both parties.
- Dark and Troubled Past: The worst in the game. Zulf's nearly a Cosmic Plaything.
- Despair Event Horizon: Was in the midst of one when the Kid showed up, waking up on the morning of his wedding party to find a world in ruins, everyone dead, and his to-be wife's ashes scattering at his touch. According to Rucks, he was just about to "throw it all away" before the Kid showed up.
- Face–Heel Turn: Goes to the Ura and convinces them to ransack the Bastion after finding out from Zia's father's journal that Rucks and the other Mancers created the Calamity cannon.
- Friendly Enemy: To the Kid and Zia. He doesn't want to harm them, necessarily. He just wants to see the Bastion fall, and perhaps take vengeance on Rucks.
- Gentleman and a Scholar: And an important force in contributing to detente between his people and Caelondia before the Calamity.
- Heel–Face Turn: If you decide to rescue him from the Ura.
- Maligned Mixed Marriage: For all that the setting plays up the Ura-Cael tensions, this is happily averted in the backstory. Zulf and his fiance don't seem to have run into any trouble for getting married from either direction. Unfortunately...
- Real Men Cook: If Zulf is saved and the player then goes with the Evacuation Ending, he supersedes Zia as the cook for the group.
- Reasonable Authority Figure: Raised by a Cael man, he moved to Caelondia and worked, with apparent success, to promote a peace based on mutual respect and coexistence. The Calamity breaks him and the awful truth about it and the futility of his past work breaks him again.
- Smoking Is Cool: His pipe.
A young Ura girl the Kid encounters in Prosper Bluff.
- All the Other Reindeer: She is an Ura raised in Caelondia who knows next to nothing about her cultural heritage. It still wasn't enough to keep people from messing with her.
- Audience Surrogate: Of a sort. Turns out she's the one Rucks is narrating the story to,
- Break the Cutie: Her would-be boyfriend sold her and her father out to the authorities, saying they were Ura spies. This after more or less insulting her father indirectly and planting the idea of escaping to the Terminals in her head which led to her arrest in the first place.
- Broken Bird: Bad things have happened to Zia.
- Dark and Troubled Past
- Elegant Classical Musician: A harp guitar.
- Foil: She wants to move forward in life while Rucks wants to rewind things, and they each represent the two endings.
- Lethal Chef: A variation when the Kid uses her stockpot in the Bastion. While the Kid seems happy enough to eat the food, it slams the door hard on its way out, as it functions as a portal to Who Knows Where, and Rucks comments on it when you keep hitting the outhouse.Rucks: Seems Zia's cooking got the best of him.
- Suddenly Voiced: While you do hear her voice when she sings, she also talks to you at the very end. Before that, Rucks voices what she says.
- Unwitting Instigator of Doom: Specifically her father's journal, which Zulf reads. As she can't read the language, she had no reason to even suspect it.
- Applies earlier than that. Her actions before the Calamity forced her father to work with the Mancers to keep her out of being arrested. In revenge, he modified the device that caused the Calamity to destroy Caelondia along with the Ura causing the events of the game. She of course had no idea any of this would happen.
- World Half Full: Her opinion of the world after the Calamity. She represents the Evacuation choice.