No More Room in Hell 1.15 Overhauls Networking, Adds 64-bit and Vulkan Support

The first thing most players will notice about update 1.15 is what disappears: the need to configure port forwarding. Steam Networking now handles connections, and a new menu in the Create Server dialog lets hosts choose between public, friends-only, or unlisted servers without touching a router.

Below the surface, the update represents a broad Source Engine upgrade with fixes concentrated on prediction accuracy — the logic that keeps what a player sees locally in sync with the server's authoritative state.

What changed

Engine and rendering

• 64-bit binaries are now launched automatically on 64-bit operating systems
• Vulkan renderer added and enabled by default on Linux
• Bicubic lightmaps and radial fog imported from the Half-Life 2: 20th Anniversary Update
• Borderless window option added to video settings
• UI scaling added for high-resolution screens
• Game now launches in native resolution by default instead of 640×480

Networking and prediction

• Steam Networking replaces the old port-forwarding model
• Improved networking precision for local player positions
• Fixed a prediction bug where client-side player movement was not factored into non-player actions
• Fixed position variables failing to sync correctly with the server in certain situations
• Fixed player hull mis-prediction causing per-frame rollbacks when crouching or near walls
• Fixed base velocity (conveyors, moving items) drifting out of sync between client and server

Other additions and changes

• Single-player games can now be paused
• Active Workshop map is distributed to connecting players on local servers
• Difficulty is now displayed in the server browser
• viewmodel_fov ConVar is now saved to user config
• Certain HUD elements hidden during suicide blackout

For a game built around cooperative survival, the cumulative effect of tighter prediction and frictionless server hosting could meaningfully reduce the jank that has long accompanied online sessions.