A Wand and its Contract
When a Wand is made by its craftsmaster, a part of the crafting is for it to come under Contract with Guardians. Thus, the created wand can only be used on Floors where it has a Contract with a Guardian. If a Wand is under a contract of the Guardians of Floors 2-31, then it will not be able to manipulate any Shinsoo on the 32nd Floor and beyond.
The Contract not only specifies the Floor(s) which the wand can be used, but also the fixed amount of Shinsoo that can be manipulated. This limitation is likely specified using the three terms for measuring Shinsoo: Baang, Myun and Soo.
Notes and Trivia
- Yu Han Sung owns a 10S-Rank Wand. This calibre is of extreme rarity in The Tower - most likely binds a contract for every Floor and can manipulate quite a bit of Shinsoo.
- Wands can be in any shape as seen by Yeongsuk's rings.