---
id: server-architecture/003
title: Tick-rate / real-time-vs-lazy-evaluation memo
epic: server-architecture
state: done
priority: 3
blocked_by: []
estimate: S
created: 2026-08-05
updated: 2026-08-02
claimed_by: null
claimed_at: null
delivers: []
review_artifact: null
---

## Resolution (2026-08-02)

**Decided, not written as originally scoped.** A direct architecture conversation settled concrete tick rates without the survey memo ever getting written: **simulation at 20 Hz, network snapshots to clients at 10 Hz** (with ~100 ms client-side interpolation), **field diffusion at 2–5 Hz if fields survive at all** (they mostly don't — see task 001's resolution). The lazy-evaluation half of this task's original question is answered more fundamentally than "which systems can skip ticks while unwatched": **an empty world is a frozen world** — no simulation runs at all while a world has zero players in it, so there's no "far-off unvisited region ticking slowly" case to design for; there's simply no ticking until someone's there.

Full decision recorded in `server-architecture/overview.md`'s "Netcode" and "Persistence" sections — read that, not this note, for the actual architecture.

## What to do

Survey how much of the simulation genuinely needs a fixed real-time tick versus can be lazily evaluated (e.g. only recompute a region's fields when a player is actually nearby — per `overview.md`'s open question). This bears directly on both hosting cost (`server-instance`) and on how "alive" the world feels when nobody's watching a given region.

## Definition of done

A short memo: which systems need true real-time ticking (e.g. an active battle arena) versus which can be computed on-demand/lazily (e.g. a far-off, unvisited region's slow terraforming). End with a recommended default tick strategy — a starting point for `server-instance`'s environment planning, not a locked-in architecture.

## Where the work lands

`land-of-lor` repo.

## Docs to read first

`land-of-lor/docs/README.md` §5 (fields), §7 (changing lines — the aging mechanism this tick strategy has to serve); this epic's task 001 (scaling approach) for consistency.