Netcode for honest combat

Gesture is a 1v1 arena duel where every swing is committed, so a trade only feels fair if both players’ machines computed the same fight from the same inputs. That’s why I’m building the simulation to be deterministic from the start, instead of adding networking later and hoping it reconciles.

Current thinking, loosely held:

• Determinism is the fairness guarantee. The sim runs at a fixed 60 Hz with input kept separate from simulation logic. If both peers step the same inputs through the same deterministic sim, they land on the same state without a server refereeing every hit. That’s the rollback and lockstep family, the approach fighting games use, and for a clean 1v1 it fits better than the shooter’s server-authoritative model.
• Commitment buys some slack. Attacks have real startup before the hitbox goes live, so there’s a window to exchange and reconcile inputs before anything lands. The mechanic that defines the genre also helps the netcode.
• The hard cases are at the edges: backstab validation (no teleporting grabs), trade resolution when both swings land on the same tick, and how much a roll’s i-frames can be trusted across a connection.

The discipline that matters right now isn’t the netcode itself. It’s keeping the sim deterministic and the input layer separate so P2P can be added later without rewriting combat. Networking comes last on purpose: the fight has to feel right offline first. Steam P2P is the target once it does.