The third s&box Game Jam has been announced with the theme ONE MORE ROUND and a £50,000 total prize fund. On 4 September, submissions open and users can nominate games; full rules and entry details are at https://sbox.game/jam/three.

The jam uses a changed format this time.

• 4 September — theme announced, submissions accepted, and users can nominate games.
• 28 September — the five games with the most nominations advance to the finals.
• During the finals, the game with the fewest votes is eliminated each day until two remain.
• The final two go head-to-head in the grand final, everyone votes, and the jam winner is crowned.

The total prize fund is £50,000, with prizes of:

• £20,000
• £10,000
• £8,000
• £7,000
• £5,000

The best game of the jam is decided by everyone who plays it.

• One submission per person.
• Team entries are fine, but only one person can submit.
• You must have the right to use all content in your entry.
• Facepunch's workshop content is allowed.
• The entry must be a new creation, not something you have already created.
• If generative AI is used for art or audio, entrants must say so on their entry.

Update 26.09.01 for s&box is out, led by a native Linux client and editor on Steam, a redesigned main menu with no server browser, a discovery pass that widens reach to roughly 70% of games, and a roadmap anchored by a £50,000 Game Jam starting Friday 4 September.

The game now ships a fully playable native Linux client on Steam via Valve’s Steam Runtime (sniper), with a bundled .NET runtime for distro-agnostic installs. Facepunch reports performance gains over Proton and notable improvements on Steam Deck.

The editor also runs natively on Linux ahead of schedule, with the caveat that Valve native tools such as Hammer, ModelDoc and Animgraph are not included. A macOS editor is next, helped by the engine’s .NET, SDL3 and Vulkan stack.

The main menu has been rebuilt again, putting games front and center with video previews, activity feeds and temporary music. The server browser is gone, replaced by game tiles and mounts. A new Game.Music API and MusicComponent give developers the same music tools.

Discovery now reaches roughly 70% of games instead of a fixed 31 (1.2%), mixing personal shelves like “Because you played X” and “More Genre X games” with global ones like “Trending” and “Up & Coming.” Games still missing usually lack basics like thumbnails, genres, tags or screenshots.

Settings were overhauled with search, post-processing controls and an auto-detect preset based on GPU and RAM.

Screen panels can render before post-processing; UI colors support HDR values and multipliers; CSS gradients are GPU-rendered; background-clip works; and experimental border-shape draws arbitrary polygon/circle panels with hit testing. Text and corner rendering were unified for faster, more web-like UI.

Mapping gains loop-face selection and Hammer-style Select Similar. Transform tools now respect global/local spaces for scaling and rotation, scene tabs can be reordered, and model creation can opt out of default material overrides.

The launcher has moved off Qt to Facepunch’s Panel UI system, with editor running detection, project dropping and faster startup. PanelGallery is available for testing UI. Forums were revamped, docs and release notes work as Markdown via .md URLs, and the roadmap is updated.

Breaking changes include protocol 29 removing package.base/local.base, legacy navigation type removal, SceneCamera API removals, SrgbWriteEnable removal, and ScreenPanels drawing after post-processing by default.

The next s&box Game Jam starts Friday 4 September with a £50,000 prize pool and player voting, likely alongside a free weekend or sale. A Christmas sale with Rust cross-promotion follows, then more regular jams next year. Facepunch says it remains committed to building a free, open-source, modern engine and eventually a standalone game on it.

Update 26.08.05 went live in s&box on August 5, 2026. It introduces Streamer Mode, NVIDIA DLSS support, a Vulkan 1.3 baseline, faster package downloads, and a substantial Hammer/content-creation pass. Full notes are on the s&box blog.

• Streamer Mode gives everyone — including the streamer — a generic anonymous name and procedurally generated profile picture. It won't work for every game out of the box; developers can check Preferences.StreamerMode and make sure player strings/profile pictures are never networked when it's enabled.
• The friends list now groups party members and lets you invite players from the list row.
• The main menu front page was reworked to get players into a game as quickly as possible, with further changes planned.

• Package download cap was raised from 16 to 64 parallel connections, with HTTP/2 sharing those connections instead of opening 64 sockets. Small files now download about twice as fast, and files stream to disk instead of buffering in memory — a 610MB package's heap usage dropped from 739MB to 3MB.
• Steam Controller support is in, alongside a unique glyph library for Steam Deck and Steam Controller and Switch joycon support. Controllers now report their names properly.
• Mounted game maps now ship with thumbnails; mount developers can use SceneLoader's IThumbnailProvider and the mount_generatethumbs concmd.

• Minimum Vulkan is now 1.3, matching Minecraft's current baseline. No new settings, expected performance change, or hardware upgrade is needed.
• The shader compiler moved from DXC to Slang, the same compiler used in upstream Source 2. HLSL shaders remain compatible, compile times drop by up to 25%, and Slang adds generics/interfaces plus IntelliSense support.
• DLSS is now available alongside FSR3 as an optional temporal upscaler. Expect minor ghosting/artifacts, and there is no frame generation or plans to add it.
• A texture-selection bias fixes overly smooth textures when using DLSS or FSR.
• Specular is enabled by default in complex shaders. Most materials won't change, but materials that had specular off and no roughness texture may gain plastic shine; setting roughness to 1.0 or adding a roughness texture fixes it.
• Static shadow caching renders static geometry once and only re-renders dynamic objects; Bloom 3 is easier to configure, handles small bright details, and benchmarks about 25% faster; hair transparency now alpha-clips instead of stippling when MSAA is off; and a shadow-mask rework fixes the 1-frame VR delay plus shadow acne/quad divergence.

• Hammer map compilation now builds aggregate scene objects from meshes/props sharing materials, reducing draw calls. It's semi-backported from Source 2 upstream without meshlets or GPU culling for now.
• Open-world visibility uses Deadlock's proven cluster merging. Maps must be rebuilt to benefit.
• Hammer can highlight bad faces, temporarily hide mesh faces, and received a primitive tool UX pass.
• The create-model wizard now includes import scale with unit presets.
• ModelDoc auto-fills materials by bare name when unambiguous, and decals can be created from selected textures via the context menu using suffixes like _color, _normal, _rma, _emissive, and _height.
• Collision events are batched and faster, but collision update events no longer fire for sleeping contacts; PhysicsBody.AutoSleep = false restores the old behavior. Painted clutter on published maps now loads correctly via temporary GameObject overrides.

Other highlights include CSS isolation support in the UI/panel system, MCP compile status reporting, public Index on SamplerStates, Input.SetLastAction, fur shader tinting, Quake map 6-sided skybox thumbnails, multiple asset browsers, terrain grid options, and a large set of community-contributed fixes. The update also removes the DXC dependency, dead D3D11 backends, and the C++ ATL dependency.