One-command local Arma 3 multiplayer test environment for modders
Launch a dedicated server plus two Arma 3 clients with a single command, reproducing HEMTT mod resolution and loading order exactly. Developed by DiGii for HEMTT-based projects, a3rig runs as a Windows command-line utility and tails the server log to the console for live debugging. It checks pre-launch settings and uses separate Arma profiles per client, making it suitable for mod developers and mission testers who need rapid, repeatable local multiplayer tests.
What does a3rig actually do?
a3rig automates a full local multiplayer stack by launching a dedicated Arma 3 server and two client instances from inside a HEMTT project. It reproduces HEMTT's mod resolution and loading order so the local test matches the build, and it attaches per-client Arma profiles to avoid configuration conflicts. The tool runs from the command line, which lets it integrate into scripted workflows and local test sequences.
Does it slow down your system during a test?
System impact depends on the number of Arma instances because a3rig launches multiple full game processes plus a server. The source notes that a machine with adequate RAM and CPU overhead is recommended for smooth testing; therefore the tool itself adds no hidden background services, it simply starts the required processes so resource use mirrors running Arma manually.
Is it safe to use on a development machine?
a3rig avoids overwriting project state by using separate profiles for each client and by reproducing HEMTT's mod resolution instead of altering the build. It also tails the dedicated server log to the console for real-time debugging and performs pre-launch configuration checks to flag settings that commonly break local rigs, which reduces the risk of silent misconfigurations during tests.
Do I need technical knowledge to operate it correctly?
Some familiarity with HEMTT and command-line workflows is required, since a3rig runs from within HEMTT projects and expects an existing Arma 3 installation. Its CLI nature favors developers and technical testers who script or automate tasks; casual users without HEMTT experience would need to learn the HEMTT project layout before the tool can reproduce build parity reliably.
a3rig is a practical, developer-focused tool with one clear trade-off
a3rig is a focused utility for Arma 3 mod developers who use HEMTT and need fast, repeatable local multiplayer tests. It reliably reproduces build settings and supplies live server logs, but it requires a system with enough CPU and RAM to run multiple Arma instances. Use it when you need exact mod parity in local network scenarios and have a development PC capable of hosting several game processes concurrently.
