For a safer room-scale experience, the HTC Vive's Chaperone is your friend!
No matter how expansive virtual worlds become, real-world space is always something we have to consider with VR. The HTC Vive's room-scale feature is a great example of this, offering full-body VR experiences – provided your play space meets the minimum spatial requirements. To reduce the chance embedding a controller in your wall, the HTC Vive comes with a play-space tracking system. Known as the Chaperone, this outlines the edges of your place space in VR, giving a rough idea of your real-world position.
Using SteamVR, this Chaperone can be customized to your liking. Although changing its appearance isn't recommended for those new to VR, it's a great way for advanced players to witness a more immersive experience.