Hell Let Loose Vietnam Tunnels: The Tunnel System Explained
The tunnel network is the NVA/VC’s answer to US air mobility — underground spawn infrastructure that turns “cleared” ground into contested ground. This page covers the confirmed mechanics and the launch-build quirks players are searching about. Last updated: August 14, 2026.
What tunnels do
- Tunnels are communist-faction spawn infrastructure: built by the appropriate roles, they let squads spawn and reposition below the surface, emerging behind or inside sectors the US thinks it holds.
- They pair with the standard garrison system — “connect garrison to tunnel” searches reflect the real play pattern of chaining surface and underground spawn logistics into a network.
- Placement has terrain rules: entrances need valid ground, and the launch build’s “can’t place tunnel” reports are usually terrain-validity rejections (steep slopes, rocky ground, too close to enemies or other structures) rather than a bug — reposition a few metres and retry. Genuine placement bugs are being tracked in the launch known-issues thread.
Playing the tunnel game (NVA/VC)
- Build depth, not lines: a single forward tunnel dies to one sweep; a network with fallback entrances survives.
- Place entrances in vegetation and defilade — an entrance visible from a helicopter is already dead.
- Coordinate with officers: tunnels are squad-serving infrastructure, and unannounced tunnels get wasted.
Sweeping tunnels (US)
- Treat every quiet retaken sector as un-swept: tunnels repopulate it.
- Grenades and close-quarters kits clear entrances; engineers deal with the structure.
- Sweep before pushing past — the classic launch-week wipe is a US push evaporating when a tunnel spawns a squad behind it.
Launch-build notes
Tunnel-related searches (“cant place tunnel”, “tunnel tutorial”) spiked at launch; the in-game tutorialisation is thin, which this page exists to patch. Mechanics details will be expanded as patches land — tracked on the updates page.
Related: factions · classes & roles