How to Join Grounded 2's Rot and Ruin Public Test and Beat Its New Centipede Boss

Obsidian Entertainment pushed a sizable new build to Grounded 2's opt-in test branch on October 6, and it drops players into a part of the backyard that longtime fans of the original game have been waiting to see again. The Rot and Ruin Public Test Build, versioned 0.6.0, turns the Woodpile into a termite-infested danger zone, adds a new boss fight, and hands players a shotgun-toting combat buggy to deal with the swarm. None of it is final, and none of it has reached the live game yet, but anyone willing to opt into the test branch can try it today.

Here's what the update actually adds, how to get into the test build safely, and what to know before picking a fight with its new boss.

Why Another Public Test Matters

Grounded 2 has been in Early Access on Steam and Xbox Game Preview since July 2025, and Obsidian has shipped nearly every major content update the same way: a public test build first, then a wider rollout to the main branch once the worst bugs are sanded off. Buggy Racing, the Beat the Heat heatwave update, and Into the Abyss — the studio's largest update to date, adding the underwater zone this patch expands — all went through the same opt-in testing period before landing for everyone. Rot and Ruin is following that pattern, which means the Termite-infested Woodpile and its new boss are likely still weeks away from a full release, giving testers an unusually long runway to learn the fight before it counts.

How to Join the Rot and Ruin Public Test

Grounded 2 has run opt-in test branches for every major content drop since Early Access launched, and Rot and Ruin works the same way. On Steam, right-click Grounded 2 in your library, open Properties, select the Betas tab, and switch to the public-test branch; the game will update to version 0.6.0 automatically. On Xbox, testers join through the Xbox Insider Hub, which Obsidian has used to distribute every prior public test build alongside the Steam branch.

Obsidian's own warning is worth repeating: this is a development build, features can change or break, and progress made on the test server may not carry over when Rot and Ruin eventually ships to the main game. Players who don't want to risk their primary save should start a fresh character on the test branch rather than importing an existing base.

Termites Take Over the Woodpile

The headline addition is a full Termite enemy family moving into the Woodpile, structured like a real colony: Workers and Soldiers patrol the nest while a Queen anchors it from inside. Players who push far enough into the infestation will run into the Centipede Boss Fight, a new set-piece encounter that drops its own mutation, a trinket, and a full equipment set once defeated, including a Centipede-themed weapon staff, an armor set, and three pieces of Centipede-branded furniture (a cauldron, a candle, and an apothecary station) to decorate a base with, plus a stuffed trophy and wall mount.

A strange addition sits alongside the Termite family rather than inside it: OGRR King, a named creature Obsidian hasn't explained in the patch notes beyond listing it under the same section. Testers should expect it to be tougher than a standard Worker or Soldier termite given where Obsidian filed it.

The Centipede set is a meaningful jump for anyone still running early-game gear. A dedicated weapon staff and full armor set from a single boss fight is a bigger reward than most of Grounded 2's existing mid-game encounters offer, and the furniture pieces give base decorators a reason to farm the fight more than once even after they've got the gear they came for.

The Potato Beetle Buggy and Abyss Upgrades

Fighting through a termite swarm on foot is rough, which is presumably why Rot and Ruin also introduces the Potato Beetle Buggy, a combat vehicle built around a shotgun-style turret for clearing out insects that get too close. Its charge projectile is built for crowds, hitting multiple targets in a single shot, and the buggy can refill its own ammo by driving over and pulverizing enemy corpses rather than forcing players to carry extra supplies.

The buggy joins a growing garage of insect-themed vehicles Obsidian has added alongside the Ladybug, Ant and Toe Biter Buggies earlier this year, but it's the first one built around ranged combat rather than gathering, swimming or racing, giving solo players a way to handle a swarm that's otherwise built for a group.

The Abyss, the underwater area Obsidian added in the Into the Abyss update earlier this year, also gets a pass in this build: a new ore called Bismuth, diggable chests scattered through the area, geysers that now put out a warming effect instead of just venting, and general navigation fixes for a zone players have complained was easy to get lost in.

Collectibles, Base Painting and Gear Upgrades

Beyond combat, Rot and Ruin adds a handful of systems aimed at base-building and completionists. Eight SCA.B 2K color schemes are scattered around the Park to collect, alongside five figurines that can be built into display statues back at base once found. A new upgrade station called the Yoking Press lets players push existing gear through higher tiers rather than crafting replacements from scratch, and a tool called the Splotcher finally brings base painting to Grounded 2, with six colors available in this build.

New craftables round out the patch: Termite Delight, a consumable made from the new Termite enemies, and Perfect Dodge, which grants a brief window of total damage immunity without consuming stamina, letting a well-timed dodge flow straight into a counter-attack.

Tips Before You Take On the Centipede

• Expect the Woodpile's termite density to be heaviest near the Queen; clear Workers and Soldiers in smaller groups rather than pulling the whole nest at once.
• Craft or find the Potato Beetle Buggy before attempting the Centipede Boss Fight — its turret and corpse-refill ammo loop are built specifically for swarm fights like this one.
• Keep the new Perfect Dodge craftable on hand for the boss encounter; a no-stamina-cost dodge that opens a counter-attack window is a meaningful edge against a brand-new fight nobody has fully mapped out yet.
• Treat the test branch as disposable. Obsidian has said test-server progress may not transfer, so don't invest hours into a base you'd be upset to lose.

Obsidian hasn't announced a release window for Rot and Ruin's move from the public test branch to the main build of Grounded 2, following the same pattern it used for the Buggy Racing and Into the Abyss updates earlier this year, each of which spent weeks in testing before launching for everyone on Steam and Xbox. For now, the termite invasion — and its new boss — is only live for players who opt in.