The current storefront answer
Steam lists Cross-Platform Multiplayer for Hell Let Loose Vietnam, and the Xbox store lists Xbox cross-platform multiplayer. The official game and platform material identifies Windows PC, PlayStation 5 and Xbox Series X|S as the supplied platform set. Those are the current product signals used for this page.
The sources do not provide a complete matrix of every party, server, account or input rule. This page therefore confirms the listed cross-platform feature without promising a specific pairing behavior that the collected material does not spell out. Check the live platform UI for the final connection flow.
What the historical playtest adds
The supplied official crossplay brief describes a playtest in which crossplay was live across the platforms and servers were marked for console-only or full crossplay. That is useful evidence that the team tested the system, but it is a historical playtest message rather than a complete post-launch rulebook. The current store listings are the safer basis for the release feature claim. It should be read as background, not as a current filter guarantee.
Do not carry every playtest label into a current server guarantee. A test can have temporary filters, known issues or a different matchmaking arrangement. The source boundary is visible here so players can distinguish “tested during the playtest” from “listed for the released product.” The live platform UI remains the final check.
How to read the platform set
PC is represented by the Steam listing, while PS5 and Xbox Series X|S are represented by their platform store pages. The Xbox store also lists Xbox Play Anywhere and cloud capabilities, and the PlayStation store lists PS Plus requirements and DualSense features. Those account and hardware conditions remain platform-specific even when multiplayer is cross-platform.
If a friend cannot join, check the current platform account, subscription, server and version conditions before assuming the cross-platform feature is absent. The supplied material does not confirm a universal quick-join path or a single cross-platform party rule. Keep the troubleshooting question as narrow as the evidence.
Cross-platform gameplay context
The official game page describes 50v50 battles between the NVA and US Armed Forces across six large-scale maps and six modes. Cross-platform play therefore connects players to the same squad-and-objective structure, including helicopters, tunnels and patrol boats. It does not change the confirmed purpose of those systems.
Use the beginner and onboarding pages to learn the team flow before coordinating with friends on another platform. The need to communicate, follow an objective and choose a useful role remains the same. Platform connection is the access layer, not a replacement for battlefield information.
What this page does not promise
This page does not promise identical settings, voice features, input matching, cross-progression or a specific server filter beyond the platform listings and the historical playtest evidence. Those details are not confirmed in the supplied sources. They should be added only when an official current page states them.
For current behavior, open the Steam, PlayStation and Xbox listings and the official update channel. If the feature changes, date the new statement and distinguish it from the old playtest report. That is the only reliable way to keep a cross-platform answer current.