From AmtWiki

The practice of an amtgard chapter switching kingdoms on a regular basis for any number of inappropriate reasons, such as personal grudges, desire for more awards (even knighthood), or even whether a given weapon is allowed.

This can happen anywhere, but was particularly a problem in the pacific northwest, where the Kingdom of the Mystic Seas and the Kingdom of the Valley of the Silver Rains used to exist in relatively the same area, until they finally unified as Blackspire.

Kingdom-Hopping as mentioned is an entire chapter switching kingdoms, even it if it motivated by just an individual. If an individual swaps park, that is termed Park-Hopping.