Party trick
From Dragon Quest Wiki
A Party trick is a specific set of motions the Hero can act out in Dragon Quest IX: Sentinels of the Starry Skies.
Many Party tricks are known at the start of the game, but many others can be learned through quests and other sources throughout the game. Party tricks serve no major purpose in the game, but are used within certain quests and as a means of communication with other players in multiplayer.
For a full list of party tricks, see List of party tricks in Dragon Quest IX.