Vault of Glass is in the weekly legacy rotator, which means Master Mode is not available until Vault of Glass is the featured Legacy Raid. Bungie TWAB : [quote]For those wondering about the weekly rotation, this particular inclusion will have a chance to feature all raids and dungeons not listed as the Seasonal rotation. Want to revisit the Vex in Garden of Salvation? Do it! Want to go toe-to-toe with Riven because you like to feel hungry for that wildly impressive (and stressful as all heck for players like me that are prone to panic) final encounter? Weird, but get on with yo’ brave and Light-driven self. Get that bread. Rewards, what’s different there? For the weekly rotation, completing the final encounter in any of the chosen raids or dungeons will award a Pinnacle drop from a Weekly Challenge. For any raid or dungeon that offers a higher difficulty, such as Master Vault of Glass, that higher difficulty will also be available to select should players be itching for an additional challenge. [/quote] [url]https://www.bungie.net/en/Explore/Detail/News/51241[/url]