"Jester" (ジェスター Jesutā) is an archetype of Spellcaster monsters used by Lazar in the Yu-Gi-Oh! 5D's anime. They focus on loading your Spell & Trap Zones in order to power up "Jester Lord" or "Jester Queen", as well as clearing the field of monsters to allow "Jester Lord" to attack directly, as its effect does not work if it is not the only monster on the field. In the manga, Lazar uses a sub-archetype, "Jester Puppet".
The main strategy of this Deck is to keep "Jester Lord" as the only monster on the field, by destroying/bouncing/banishing/tributing your opponent's monsters and preventing their summons.