Cross-platform play was once a technical and business headache. Now it's table stakes. Lucas and Luna look at how studios like Epic Games, Microsoft, and Sony navigated the shift — and why smaller developers are treating full cross-play as a baseline feature, not a differentiator. They trace the turning point: Fortnite's 2018 cross-play beta, the 2021 Microsoft flight simulator data showing 40% of new players came via cross-play invites, and the backend middleware that makes it possible today. They also unpack the tricky economics — lost hardware-ecosystem lock-in versus extended game life and bigger player pools. Specific numbers: Epic reported that cross-play increased Fortnite's daily active users by 25% within three months of launching the feature. By 2026, nearly 80% of new multiplayer releases support full cross-play across at least two platforms. A concrete listen for anyone who builds, invests in, or just plays multiplayer games.