ARCANUM — Development Log

A Horror Tarot Experience for Android

The Concept

What if a tarot reading app became self-aware? What if the cards started reading you?

ARCANUM began as a simple idea: create a tarot app that slowly descends into psychological horror. The player takes on the role of a fortune teller, giving readings to "Seekers" through a chat interface. But as the readings progress, something sinister awakens within the deck itself.

The horror isn't jump scares or gore—it's the creeping realization that you've lost control. The app starts responding on its own. Text becomes corrupted. Your phone vibrates in patterns that feel too organic. And the Seeker on the other end... something is very wrong.

What We Built

The Core Loop

1. Welcome Screen — Atmospheric intro with pulsing gold symbols
2. Seeker Chat — Text-based interaction with a desperate stranger
3. Card Drawing — Tap to reveal three-card spreads (Past, Present, Future)
4. The Turn — Horror elements escalate as readings continue
5. Endings — 10 different fates based on player choices

The Cards (78 Total)

We implemented a full tarot deck:

• 22 Major Arcana — The Fool, The Tower, Death, etc.
• 56 Minor Arcana — Four suits, each with a unique horror theme:
  • Cups: Drowning, tears, emotional suffocation
  • Wands: Obsessive fire, burning ambition gone wrong
  • Swords: Paranoia, nightmares, mental fracture
  • Pentacles: Greed, decay, material corruption

Every card has two interpretations: a "light" reading and a "cursed" reading that reveals itself as horror takes hold.

The Seekers

Three characters, each with their own tragedy:

Each Seeker has branching dialogue and unique horror moments.

Horror Effects

We weaponized every sensor:

• Haptic Feedback: Heartbeat rhythms, scratching sensations, static bursts
• Visual Glitches: Screen flicker, horizontal distortion, camera flash simulation
• Text Corruption: Zalgo text that spreads like an infection
• Audio Cues: Scratching sounds, distant screams, ambient dread

New Features (Phase 3)

• Daily Ritual — One card per day, no horror, just reflection
• Grimoire — Collect all 78 cards, track your discoveries
• Fates — Gallery of all 10 endings (3 Bad, 3 Good, 3 Neutral, 1 Secret)
• Options — Sound, vibration, and horror intensity controls

Technical Highlights

Stack: Kotlin, Jetpack Compose, Material 3

Key Decisions:

• Used rememberInfiniteTransition for smooth horror animations
• SharedPreferences + Gson for persistent progress
• Composable horror effects that can be layered on any screen
• Modular Seeker system for easy content expansion

Challenges Solved:

• Fixed LazyColumn key collisions causing crashes
• Resolved variable shadowing in graphicsLayer calls
• Balanced horror intensity to be unsettling without being unplayable

What's Next

Phase 4: Audio Expansion

• Ambient background tracks that shift with horror level
• Card flip sounds
• Whisper effects that feel too close
• Heartbeat audio that syncs with haptics

Phase 5: Polish

• Fake notification popups ("You have 1 new message from: UNKNOWN")
• Social sharing for readings
• Reversed card interpretations
• More Seeker stories

Final Thoughts

ARCANUM isn't about winning. There's no high score. The only reward is the experience—and the lingering unease after you close the app.

The cards never lie. But sometimes, you wish they would.