Gao usually uses the "Gao Formation" - a formation in which a player has 2 monsters and an item equipped without a monster in the center thus leaving him open to direct attacks. He incorporates many defensive cards (some of them having Move) to compensate for this.
Gao mainly uses Dragon World decks featuring Drum Bunker Dragon as his Buddy. Due to his lack of experience in deck building, his decks are built by Baku Omori. As the series progresses, Gao's decks change to reflect Drum's changes and evolutions, using different Worlds occasionally.
Gao's first deck was themed around the Armordragon attribute. He mostly focuses on quickly dealing damage, mainly by attacking as many times as possible per turn, often leaving his center area open to attack with items. After obtaining Gargantua Punisher!!, Gao gives more focus on finishing the game with Punisher!!, so he added Steel Fist, Dragoknuckle to help increase his gauge quickly. This deck sets Gao's standard strategies.
Baku and Kuguru later designed a new deck for Gao to use in the ABC cup so as to cover Gao's weakness of leaving his center area open too often by including monsters with the Move ability and adding more spells that increase attack and defense like more Dragoenergy and Wrath of Dragon.
"Showering the sky with scorching sun rockets! Soleil Dragon Deck, Luminize!"
The night before going to Sengoku, Baku and Kuguru build a magic world deck for Gao focused on drum's new form and his ability by adding cards that would help decrease his life and spells that would help him pay the gauge cost.
"Unleash fighting spirit, bravery and courage! Luminize! The mighty Magic Guts!"
In episode 31, Gao's Dragon World deck once again changes, this time to the Thunder Knights archetype, with Drum's evolved form, Thunder Knights, Drum Bunker Dragon. This deck focus on the monster's Move ability, creating a balance of offense and defense. By using the set spell, Thunder Formation!, he is able to increase his gauge when a Thunder Knights moves to any position. It also acts as an impact card, letting Gao check any 3 cards on the top of his deck after he and all of his current monsters on the field are done attacking,allowing him to call another monster with Thunder Knights on its name to attack the opponent again.
In episode 33, Gao uses a Dungeon World deck focused on the Adventurer attribute, with Brave, Drum as his buddy, which shows Drum's training results while in Dungeon World. This deck uses many mini games,like 'Rock,Paper,Scissors', relying on luck to activate certain monster effects and making Link Attacks to activate his Adventurers' abilities. His main item is Brave Equipment, Glory Seeker, allowing him to revive with 3 life points with its effect should his life reach 0.
Gao's second objective with this deck is to make the fight more fun and enjoyable for him and his opponent with the various mini games it offers as well as card versions of many of his friends who comically often excite/confuse their real counterparts and quickly embarrass them later.
"If you take a chance and reach for the sky, the clouds will unmask the sun! Now Luminize! Brave Soleil!"
After realizing Disaster's true intention in episode 45, he obtains a new deck. This deck returns to Gao's original Armordragon focus and Drum's base form as his Buddy again, but its improved with new ways to use his "Gao Formation" style as well as support for Drum's varied forms while also supporting his new Roaring Slash!! Gargantua Punisher!!. Gao now uses several Size 0 monsters which after attacking return to his hand and deck allowing him to attack 4 times per turn and still use his item, while Dragon Return System increases his Gauge every time they attack.
While fighting Death Sofia, he uses a Hero World deck with Buddy Police, Decker Drum as his buddy. His ability allows him to pay 2 gauge to destroy a monster. And Gao his an impact, Rampage Blaster! used to deal 3 damage only if he transforms himself into Explosive Takedown, Rampage Sonic. He used this deck again in his fight against First Omni Beast Lord, Ziun. After discovering that Tenbu is useful for all flags, he added it to his deck. Mach Braver's effect allows Gao to call him to the center so he can block an attack. After Drum obtains a new form, Gao rebuilds his deck. Drum's new skill allows him to stand after destroying a monster, and Gao's new transforming card, Fiery Inspector, Prominence Burst, gains a critical after a monster is destroyed. For his fight against Kazane, he added Count Dawn to his deck so he could see Kazane again.
"Emergency Launch, from the eye of a storm! Luminize! Beaming Sunshine Guardians!"
His deck goes through some improvements, focusing on gaining abilities through link attacks, preventing damage with Sun Stone, Bal Flame, and using the Dragon Force to his full potential. During his fight with J Genesis, he obtains Super Sun Dragon, Balle Soleil.
"Colliding fists! Connecting hearts! Shine brightly! Super Sun! Luminize! Bullets of the Sun!"
For the final battle against Kyoya, his deck improves focusing on using the spell, Sun Deity's Choice, in order to use the powerful impact, Balle Soleil, "Eternal Bal-Blaster!", using the spell's ability to lead him to victory. He also uses all the Impacts and forms he required during his final fights with Bal Dragon.
In the Japanese version of the anime, Gao's first deck was called "Bakudora" (爆ドラ), an obvious pun on the fact Baku build his deck. This pun was lost in the English version of the anime, where the deck's name is directly translated to "Dragon Blast Fury", as Baku (爆) in Japanese means "Explosion", while Dora (ドラ) means "Dragon" in terms of transcription "doragon (ドラゴン)".