Casualties Unknown Wiki

Characters

Expie in Casualties Unknown

The health panel of an Experiment, listing height 148 cm, age 13 and a specimen number beside a body diagram showing wounds
The health panel names your Experiment and gives its height, age and specimen number. Official Steam screenshot, © Orsoniks / Oro Interactive.

Short answer: an Expie is an Experiment, the disposable test subject you play in Casualties Unknown. The game calls them experiments and players shorten that to Expie. It is the first of three playable characters and the only one in the demo. confirmed

The reveal post describes an Experiment as a build-up of genetic mutations, used as a disposable unit for dangerous work, and sent with thousands of others to recover lost cargo from a foreign planet. confirmed

What is an Expie in Casualties Unknown?

An Expie is your character at the start of every run: a small black-furred creature with an orange-tipped tail, as the store art shows. Each run gives you a new individual. The health panel lists its height, age and specimen number, such as “148cm, 13y, #32395” in an official screenshot. confirmed You never carry a character between runs, so treat each one as expendable. The game certainly does.

The game does not treat them as simple avatars. They talk, panic and react to pain. In official screenshots, an Experiment shouts “GET AWAY!” at an attacker and says “I want to eat!” while starving, and your tutorial includes a way to skip part of the First Aid course by barking. confirmed

What can an Expie do?

Ability Detail Status
Fight Bare claws and any weapon you pick up confirmed
Traits Intelligence, Strength and Resilience rise during a run confirmed
Craft Recipes are limited by Intelligence confirmed
Climb Wall jumps, with coyote time since 7.0 confirmed
Ragdoll Hold X to go limp and wiggle through tight gaps confirmed
Read health A chip shows vitals in the health panel, unless you play unchipped confirmed

Players point out that an Expie can stay on its feet with injuries that would finish most game characters, because damage is spread across limbs and blood volume rather than a single bar. unverified Survival still depends on you noticing problems. See limb damage and bleeding for what to do first.

How do you unlock the other Casualties Unknown characters?

The developer’s September update says you choose between the Experiment and two other species when you start a run, and that you unlock each one by finishing a run with the previous character. confirmed In other words, beat the game as an Expie first. Each character has its own stats and gimmicks, and more may come after launch, though the developer said not to count on it. confirmed

Order Character How to unlock
1 Experiment (Expie) Available from the start
2 Milky Finish a run as the previous character
3 Dune Finish a run as the previous character

The unlock order above reflects the order in which players have seen these characters revealed. The September post only says “previous character”, so check the character screen in your own game. reported

Why are they called Expies?

It is a nickname from the community, built from “experiment”. The name shows up in forum threads, video titles and search terms, while the game itself uses “Experiment”. Searches for expie casualties unknown far outnumber the formal word, which is why you will see both in guides.

Most fans refer to Expies as they or it. The game’s own design treats them as lab-bred creatures rather than people with a human background, and a long forum thread on what keeps them going argues over how much they understand about their situation. reported

Why does an Expie’s mood matter so much?

Because the character reacts to what you do to it. Pain, corpses and bad food push mood down, and the store page warns that “too much doom and gloom will make your life harder”. Players also link low mood to worse odds in a last stand. reported Good food and rest lift it. The mood guide lists what moves it, and is it a furry game covers the upsetting side of the character’s dialogue if you are deciding whether to play.

What should a new Expie do first?

Your first minutes shape the run. Move your light, break the pod floor for plastic, gather foliage and make a canteen, in the order given by the beginner guide. Spend your early Intelligence gains on recipes that keep you alive, as the crafting guide explains.

Can you change how an Expie looks?

Not in the base game, beyond what the run gives you. Mods can replace the sprites, and one mod adds 14 further species. See skins for how to swap them, and note that those mods were built before the full release.

Is an Expie stronger than the other characters?

We cannot say yet. The store page calls your character “a creature capable of reason” that survives by using tools, and promises three characters with “their own distinct playstyles”. confirmed Until the full game is documented, assume that an Expie is the baseline the other two are balanced against.

Sources

Last checked 9 November 2026. Marks: confirmed = official notes, in-game text or a recording of the game; reported = two or more players; unverified = one source.

  1. September Progress Update, Steam · characters, unlocks
  2. Game Reveal and Demo launch, Steam
  3. Casualties: Unknown on Steam · premise, screenshots
  4. 6.1 Demo Patch Notes, Steam
  5. Steam forum: what is the point of continuing on? · player discussion
  6. Steam forum: expies compared with slugcats · player opinion