Alright right on.Well, it's pretty simple; you use metal cards that have fuuinjutsu seals inscribed into them for use. By activating these seals, you create one of three types of effects: Monster effects, traps and spells.
The first of the three summons various shaped barriers from the seals that may have inherent abilities dependent on the seals that triggered them. The second are as the name suggests, traps that activate under predetermined conditions to cause generally negative effects on them and the last are essentially augmentative effects such as infusing nature manipulations into them, supplementing the damage output or things of similar natures. Though this sounds expansive, it's all related to the specific card type with each being capable of specific commands ( summoning monsters/enhancing said monsters or creating weaponry/hindering opponents or the field).
Now, would you like to try to pass a test, or defeat the king of games himself (me) in a 2/3 battle