---
term: deck
category: spatial
status: canonical
authority: world.elonn.local
---

Deck

A navigable ordered collection of surfaces within a region. A deck represents movement through contextual space.

Examples:
- discover deck
- communication deck
- navigation deck
- system deck
- calendar deck

A deck is NOT:
- a carousel (content loops; decks represent distinct contextual states)
- a tab bar (fixed navigational strip)
- a menu (command list)
- a scroll view (continuous content)

Deck orientation — the primary navigation axis:
- vertical — Elonn's initial implementation
- horizontal
- radial
- stacked

Sub-concepts:
- active surface — the currently focused surface within a deck; only one surface is active at a time
- adjacent surfaces — neighboring surfaces partially visible during navigation; provide spatial awareness and transition continuity
- deck transition — movement between surfaces; may be gesture-driven, programmatic, voice-driven, gaze-driven, or keyboard-driven
- snap threshold — normalized gesture distance required to commit a transition (typically 12–18%)
- interpolation — continuous visual transition state between surfaces; controls position, opacity, scale, depth, and rotation
- stack depth — relative visual depth of a surface within a deck
- reveal edge — visible portion of an adjacent surface; critical for orientation and spatial continuity

Allowed:
- deck
- [name] deck (e.g., discover deck, communication deck)
- deck transition
- active surface
- adjacent surface

Forbidden:
- carousel
- tab
- stack (ambiguous with call stack; use deck)
- slider
- pager

Notes:
- Decks exist inside regions. Surfaces exist inside decks.
- Elonn's initial implementation is a vertical stacked deck.

Related:
- surface
- region
- runtime
- block
- navigation