Networking specification

Multiplayer sessions, DirectPlay 3 transport, and application messages.

Wire-format detail lives in ../../protocols/ — this domain indexes behavioral context (when messages are sent, what game state they affect).

Scope

• DirectPlay 3 session lifecycle (create, join, enumerate SP) — retail build only
• Host vs client roles and lobby wizard
• Application message framing (lotr2_net_msg)
• Turn-phase and UI sync opcodes
• System message handling (player join/destroy, host migration)

GoG multiplayer uses ASIGS, not DirectPlay; it is out of scope for this domain until documented. See ../../builds.md and ../../skirmish/multiplayer-pvp.md.

Evidence

• ../../architecture/net/MODULE.md — DirectPlay entry points, send/receive
• ../../protocols/README.md — message family index
• ../../protocols/dplay.md — session overview
• ../../protocols/dplay-app-messages.md — app opcode catalog
• ../../protocols/dplay-system-messages.md — system messages
• ../../structs/lotr2_net_msg.md — app message frame

First spec targets

1. Session lifecycle — host open, client join, roster sync, transition to gameplay (cross-link gameplay MP lobby spec).
2. App message catalog — maintain and extend ../../protocols/dplay-app-messages.md; add behavioral "when sent / handler effect" columns as gameplay spec matures (Phase 7).

Spec pages

(Behavioral networking pages go here. Wire formats remain under docs/protocols/.)