Season Vault is a vault that you can access when game modes are soon to get a reset. To open it do /vault or /seasonvault or /resetvault. You must be VIP or higher in order to open the vault.
During the season of game modes you may collect items called "Seasonal Vault Items", those items will grant you access to the Season Vault at the end of every season.
CAUTION - All reset vaults are both automatically and manually reviewed before being added to new season, and any attempting to glitch in unallowed items will cause your entire vault to be deleted.
Players typically get these items from opening Promotional Crates, for more information regarding keys you may want to visit our What Can I Buy? article.
Below you will find an example on a "Seasonal Vault Access" item. You can verify its authenticity at the bottom of the information tab.
Once a new season of a game is released, you will have to wait around 2 weeks before vaults are opened again.