Hello SilentWalkerZero,
When a game has both “Playable on Xbox” and “Playable on PC,” that only means the game is available on both platforms. To actually play, you generally need to buy the Xbox and PC versions separately.
With Xbox Play Anywhere, you buy the game once and can play it on Xbox, Windows PC, and supported handhelds at no additional cost.
Halo: Campaign Evolved supports Xbox Play Anywhere, so one digital purchase covers all those platforms.
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