Dark monsters are perhaps the most numerous of all monsters. Many well-known monsters are of the Dark attribute, such as Dark Magician of Chaos and Jinzo. Fiends and Zombies are usually DARK types and so are all the Destiny Heroes and Allies of Justice. Many Spellcastera are also DARK, such as the "Dark Magician". Although LIGHT is the polar opposite of DARK, there is no true advantage over one side in the OCG/TCG, although there are cards such as "Luminous Soldier", "Penumbral Soldier Lady", "Hoshiningen" and "Witch's Apprentice" which lower the stats of the opposing attribute.
Being one of the most versatile and common Attributes, Dark monsters and the cards akin to them can work with many different Deck Types, and rarely does a typical deck lack at least one. However, it can be said that many Dark cards have something to do with Spell Cards and the like, perhaps reflective of the mysterious and shadowy nature of darkness, coupled with the great number of Dark Spellcasters. Chaos Decks favour DARK monsters as well as Light monsters, and are in fact instrumental in Summoning the key cards of the Deck (i.e. Chaos Emperor Dragon - Envoy of the End, Black Luster Soldier - Envoy of the Beginning, and Chaos Sorcerer).
A recent theme is development of Dark-attribute versions of other cards, such as Dark Armed Dragon, Dark Nephthys and "Dark Simorgh". These cards tend to revolve around removing other DARK monsters in the Graveyard from play in order to activate their effects.