Chains is an upgraded item.

Chains
“it's so dark.”
Quality (unknown)[citation needed]
Mechanic upgrade
8 Ball⨯1 →Chains⨯1 (8h) 
I don't really like working with this stuff... but I trust that you know what you're doing.

Effects

Makes your curse incurable, but drastically increases rescue luck while you have it. Use at your own risk!

— In-game description

Converts the current curse into a Shackled Curse, making it incurable. Curses received from quests can overwrite Shackled Curses as normal.[1]

Shackled Curses add 4 points of luck when rescuing, or 2 points if weakened.[2]

If the total number of luck is greater than or equal to 6, 1 luck will be decreased regardless of whether it is weakened.

History

Zoo Bot
v1.1.0 Added Chains.[3]

References

  1. 14 March 2023. Reply to @viviampersand by Colon [@colon] in the #zoo-bugs channel in the 9th Tail Bot Hub server.

    @viviampersand: shackled curses can be overridden by a quest reward. no idea if this is intentional
    @colon: yeah this was something i was considering and decided to leave in
    if you shackled your curse it usually means you dont want to overwrite it, which makes getting a curse from a quest "bad" like it should be

  2. 25 April 2023. Reply to @firefly256 by Colon [@colon] in the #zoo-talk channel in the 9th Tail Bot Hub server.

    @firefly256: @colon how much luck does chains give
    @colon: 4/2
    @firefly256: […] Is it 4 when you use Chains on a normal curse, and 2 if you used Chains on a weakened curse?
    @colon: ye

  3. Zoo changelog, v1.1.0 (released 28 February 2023):

    “Added 5 new items to the mechanic”