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.
As every game mode varies their reset times, a post may be made on the forums regarding the items that are included inside the Season Vault, and the deadline for its close.
When doing /vault or /seasonvault or /resetvault, you will be told if you are trying to introduce the wrong item if not a season vault access item, and every time you open it a message will pop-up in chat letting you know when it is going to be closed.
After the season vault closes, you will have to wait to open it back once the new season for that game mode is up, once there, you may open your season vault doing /vault or /seasonvault or /resetvault.