Entities, Movement, Placement & Attributes

1. Summary

All actors share one unified NPC model (19) — players are special-cased; monsters, townsfolk, workers, and wildlife are all npc_instances from YAML definitions.

Actors exist in the global world at (x, y, z) with orientation on the horizontal plane. Movement uses 360° facing and velocity; FOV and movement speed are first-class attributes modified by equipped item instances, skills, and effects.

No BiS gear chase — each player assembles a unique inventory of instances (18).

Attributes split into primary (core stats), derived (computed from primaries + gear), and resource pools (HP, stamina, mana). A unified modifier system (08) applies to attributes, skills, and item properties.

2. Placement & orientation

2.1 World position

struct Transform {
    position: WorldCoord,   // x, y, z, w, t
    yaw: f32,               // facing, radians or degrees 0–360° (server canonical)
    pitch: f32,             // optional: look up/down, climb, fly (default 0)
}

• Server authoritative — clients send intent; sim integrates position
• z from world strata (01): surface, underwater, underground, sky

2.2 Facing vs movement direction (decided)

They differ when strafing, backing up, knockback, sliding, mounted:

        facing (yaw) ──►
              ┌───┐
              │ P │──► velocity (may be 45° off while strafing)
              └───┘

• Move intent: (forward, strafe) in local space → world velocity via yaw
• Network: replicate position, yaw, velocity (or last intent) @ tick rate in AOI (06)
• NPC behavior — controllers set move_yaw / yaw (19 §8)

2.3 Rotation for items & objects

Items use single yaw by default (degree value on instance or template default). Structures may lock rotation to 90° steps if authored — template flag rotation_snap: 90.

2.4 Omnidirectional world vs FOV

• Cartography / map reveal — 360° around character (06) — exploration is not cone-limited
• Combat detection, stealth, “see NPC” — FOV cone from yaw ± fov/2 (attribute)
• Hearing — sphere (radius attribute), ignores FOV unless muffled

This split avoids tunnel vision on the map while keeping tactical facing matter.

3. Movement attributes

All modifiable via buffs, terrain, zones, mounts.

Auto-nav / AI pathfinding uses the same terrain move_speed_mult for Fastest (true ETA) vs Direct (shortest walkable geometry). See 51-pathfinding-route-modes.html.

4. Primary attributes (core stats)

Six primaries plus Charisma at launch are the main inputs to derived stats and skill checks. Internal scale 1–1000; UI displays 1–100. Skills use 10 achievable tiers (configurable breakpoints).

5. Resource pools (secondary)

Full tick rules, hunger/thirst, damage, durability: 15-active-stats-survival-and-damage.html.

6. Derived combat & perception attributes

Computed each tick from primaries + gear + modifiers; cached until dirty.

6.1 Offense

6.2 Defense

6.3 Perception & awareness

FOV is a stat — e.g. base 120°, eagle helm +15°, blind debuff −80°. Omnidirectional cartography unchanged (06).

7. Physical & survival attributes

8. Mental & social (optional depth)

9. Item & object attributes

Every item is a unique instance (18). Templates define schema; rolled stats live on the instance at mint.

9.1 Universal item properties

9.2 Equipment combat stats (per instance)

9.3 Tools & stations

9.4 Consumables

10. Skills (separate from primaries but linked)

Skills are trained values (0–100+) used for checks and unlocks; often gated by primary minimums. 10 tiers of mastery (display + unlock breakpoints); internal precision on 1–1000 scale.

Skill XP modifies effective skill level; primaries may cap skill training speed.

11. Modifier interaction (recap)

All attributes, derived stats, FOV, and move speeds use the shared modifier model (08 §6):

• Spells, potions, equipment, auras, zone effects, death sickness (07)
• Modifier.target examples: attr.strength, derived.evasion, move_speed_run, fov, item.mass

Recompute derived cache on equip, buff, or primary change.

12. Server & protocol notes

• Replicate in AOI: position, yaw, velocity, essential combat state
• Interest: entities outside sight_range ∩ FOV may be omitted from combat awareness but region sim still runs AI globally in shard
• Placement validation: collision mesh from chunk terrain (01); reject invalid spawn
• Item drop: find floor z + valid yaw from dropper facing

13. TUI / agent

flatland status              # primaries, pools, key derived
flatland attr list --json
flatland move --forward 1 --strafe 0   # local to facing
flatland face --yaw 270
flatland place item <id> --yaw 45

14. Phasing

15. Open questions

Resolved (2026-07-06):

16. Quick reference — attribute families

PRIMARY     STR  DEX  INT  STA  VIT  WIS  [CHA]
POOLS       HP   Stamina   Mana   Breath
MOVEMENT    walk run swim fly climb turn_rate
PERCEPTION  fov  sight_range  hearing  stealth
COMBAT      attack_power spell_power crit hit evasion armor resists
PHYSICAL    carry_max hunger thirst
ITEM        mass volume durability damage armor stat_bonuses
SKILL       (trained, linked to primaries)

Coordinates & AOI: 06. Carry mass: 08. Death penalties: 07.