Decoy Dragon Decoy Dragons name fits the artwork after you take a second look
The manga would sometimes reference simplistic games like table hockey or even toys that react to sound, some were more complex including the aforementioned card game against Kaiba or a chess like game using small monsters and while theres clearly some logic as to how the game plays out so readers can follow along, there is no design document explaining all the rules of these games simply because thats not what the manga is trying to do
Episode 87 gives us a saloon with the wonderful name of "The Classy Ass"

Recommended cards[edit] Recommended cards Cyber Dragon Cyber Dragon Core Cyber Dragon Drei Cyber Dragon Herz Cyber Dragon Nachster Cyber Dragon Vier Cyber Eltanin Cyber Jormungardr Cyber Pharos Cyberdark Chimera Cyberdark Wurm Cyber Dragon, the Luminous Mech Dragon Arcjet Lightcraft Carnot the Eternal Machine Convex Knight Division Dyna Base Galaxy Soldier Gizmek Yata, the Gleaming Vanguard Gray Layer Honest Jizukiru, the Star Destroying Kaiju K9-17 Izuna K9-66a Jokul Psychic Processor Solar Wind Jammer Therion "King" Regulus Toy Tank Chimeratech Fortress Dragon Chimeratech Megafleet Dragon Chimeratech Overdragon Chimeratech Rampage Dragon Cyber End Dragon Cyber End Dragon, the Final Strike Dragon Cyber Eternity Dragon Cyber Twin Dragon Heosvarog the Mechanical Dawn Invoked Mechaba (if using "Invoked" engine, or as a target if "Cyber Dragon Nova" is removed from the field) Pair Cycroid (with "Power Bond") Panzer Dragon (with "Instant Fusion") Arms of Genex Return Zero (using "Duality" to Tribute either "Carnot the Eternal Machine", "Cyber End Dragon" or "Jizukiru, the Star Destroying Kaiju") F.A

Whether youre deck building or combo chaining, these sleeves wont stick, split, or slow you down
You can equip Grenosaurus with Axe of Despair, making it a 3000 ATK monster