Chain grabbing is a technique in the Super Smash Bros. series. It involves grabbing a character, throwing them, and grabbing them again. This is possible because they are within range, etc. It can only be done with throws that have set knockback or with low knockback and low scaling, and most infinite chain grabs are easier done against a wall. An example is King Dedede's infinite chain grab on any character Marth or heavier against a wall using his Down Throw. The Ice Climbers can also perform chain grabs.
In SSB3DS/Wii U
Chain grabbing was virtually removed in 3DS/Wii U, similarly to how the edge grab mechanic was added. Pseudo-chain grabs still exist, however. Sheik can chain D-Throw into FF U-air into regrab, Luigi can do D-Throw into Dair into regrab, and Mr. Game & Watch can do D-Throw into Chef into Jab into regrab.