Ball 'n' Chain is a ball that has spikes on it, and rotates in place from a block. It is mostly invincible, but slowly rotates (or swings), and is generally easy to bypass. Bowser uses these as dangerous objects and weapons in his many territories. Although they are used to prevent the player from succeeding, the player can stand on the brick (which is what the ball is chained to) and will keep from being hurt by the ball. These can be found in Bowser's Castles and fortresses throughout the games it has appeared in. In most games, Ball 'n' Chains possess a similar behavior to Firebars and Roto-discs.
Super Mario series
Super Mario World
Ball 'n' Chains are first seen in Super Mario World, in this game, they are seen attached to a gray stone block spinning around. They will power-down Mario/Luigi if he touches one, whilst the Spiked Ball can harm the plumbers, the chain it is attached to is harmless and can be walked through without an issue. The Ball 'n' Chains cannot be destroyed unless the plumbers are under the effects of a Starman, additionally, the a Ball 'n' Chain can be spin jumped on without taking damage. Ball 'n' Chains are commonly found in Fortresses and Castles, one example being Ludwig's Castle.
Super Princess Peach
New Super Mario Bros.
The Ball 'n' Chain object also appeared in New Super Mario Bros. in the World 7-Castle. In this game, The Ball 'n' Chains rotate around the block quickly in this level. A Star Coin even appears on one of the blocks a Ball 'n' Chain is attached to requiring for some quick maneuvers to obtain it. Just as before, the Spiked Ball is harmful to Mario/Luigi but the chain isn't, additionally their blocks can be stood on. A Ball 'n' Chain cannot be destroyed in this game.
New Super Mario Bros. Wii
The Ball 'n' Chain object then reappears in the game New Super Mario Bros. Wii, however in this game, they are rather rare obstacles with only two appearing in the whole game. in the secret areas of Lemmy's Fortress and Wendy's Castle. In the former, the Ball 'n' Chain is seen guarding one of the level's Star Coins within some large moving blocks and in the latter, it is seen in an underwater section attached to a spinning cross-shaped pendulum platform guarding a Red Ring. Unlike the previous game, the Ball 'n' Chain can be destroyed using a Starman and unlike previous games, the chains are now attached to nails in walls rather than blocks. Just as before, Ball 'n' Chains are seen rotating and only the ball is harmful.
Super Mario 3D Land
Ball 'n' Chains appeared in their 3D debut Super Mario 3D Land, where the ball is purple with yellow spikes, and the chain is also yellow. In this game, they aren't connected with shackles, unlike Super Mario World, where they are. Also, the object doesn't spin, but instead sway back and forth in a pendulum-like way. Ball 'n' Chains are are first seen in World 1-2 and from there, are commonly found in caverns and other buildings. Ball 'n' Chains can be destroyed with the effects of a Starman, Invincibility Leaf, or Statue Leaf.
New Super Mario Bros. U/New Super Luigi U/New Super Mario Bros. U Deluxe
Ball 'n' Chains return in New Super Mario Bros. U as well as New Super Luigi U and New Super Mario Bros. U Deluxe. In these games, they are much more powerful and more deadly than they are in previous games. They have spikes all around them, even on their chains which makes their chains a hazard as well and as a result, they can't be passed through, only under. Ball 'n' Chains are only seen swaying in this game (they don't spin unlike the previous games), Ball 'n' Chains are only seen in two levels, Pendulum Castle and Impossible Pendulums. They are also indestructible and cannot be destroyed (not even with a Starman). If Nabbit runs into a Ball 'n' Chain, he will be knocked back a bit (but won't take damage). Giant Ball 'n' Chains are also seen in this game.
Mario Party series
Mario Party 10
Ball 'n' Chains are also seen in Mario Party 10 in the minigame Spiked Ball Scramble. They appear swining along the paths and players have to time their movements to avoid being hit whilst trying to stay on the track to avoid the lava, players should generally choose the path with less Ball 'n' Chains to avoid them (the paths up ahead are revealed as the screen scrolls). One touch of a Ball 'n' Chain will eliminate a player.
Mario Kart series
Mario Kart 8 / Mario Kart 8 Deluxe
A single Ball 'n' Chain also appears in Mario Kart 8 and Mario Kart 8 Deluxe in Bowser's Castle. It is seen after the sets of Podoboo Cogs amidst the jump leading to the Castle's balcony. Running into the Ball 'n' Chain will knock a racer over causing them to lose some Coins so be careful. Players can phase through a Ball 'n' Chain without an issue whilst under the effects of a Starman or Bullet Bill.
Super Mario World 2: Yoshi's Island / Yoshi's Island: Super Mario Advance 3
Ball 'n' Chains are seen in Super Mario World 2: Yoshi's Island as well as Yoshi's Island: Super Mario Advance 3. In these games, they are rather uncommon mainly being seen in Forts such as Burt the Bashful's Fort. Ball 'n' Chains are indestructible in this game and will knock Baby Mario off Yoshi's back upon contact. Mace Guy's tend to use a smaller Ball 'n' Chain as their primary weapon. Ball 'n' Chains are seen spinning around in this game and appeared to be spun around by some Boo Guys.
Ball 'n' Chains appear again in Yoshi's Story this time only appearing in two levels Tall Tower and Magma Castle, they either sway like a pendulum or quickly drop down to the floor and then slowly rise again similar to a Thwomp.
Yoshi's Island DS
Ball 'n' Chains appear again in Yoshi's Island DS mainly appearing in Castles such as Castle of the Big Burt Bros. They are also seen in caverns as well and are more common than the previous game. Just as before, they are indestructible and they spin thanks to the Shy Guys. They also behave identically to Firebars serving as an alternative.
Yoshi's New Island
Ball 'n' Chains return in Yoshi's New Island this time being slightly larger than previous Yoshi's Island games. They are seen in Forts and Caves and just as before, are indestructible and spinning as they are controlled by the Boo Guys. Mace Guys once again use the Ball 'n' Chain as their primary weapon.
The object was also found to have a small cameo appearance in the Super Mario World TV series in the episode called "Send in the Clown". While Mario travels through Neon Castle, Mario gets very closed to being hit by a Ball 'n' Chain, which drops from the ceiling, as he tries to get through a lava area.