However, ignoring the vertical space—the 'Z-axis' of the arena—is a fatal flaw that will immediately stall your progression on the competitive ladder.

They entirely bypass the river, they are immune to powerful ground-control spells like The Log and Earthquake, and they cannot be distracted by standard ground-melee troops.
The Danger from Above
If a player sends a Balloon at the bridge, and your only anti-air card is a 3-elixir Minion squad buried at the bottom of your deck, you have already lost the tower.

Because flying units avoid so many standard defensive interactions, they require highly specialized, immediate answers.
Never build a deck with only one anti-air card.Flying anti-air units (like Mega Minion) are safer because they avoid ground melee.If you place a Wizard and a Musketeer right next to each other, a single Poison spell will kill both, leaving the skies wide open. Choosing Your Air Guards
The 'Air Assassin' role (Mega Minion, Phoenix, Minions) involves playing flying melee units that fly out to directly intercept the enemy threat in the sky.

If you are playing a heavy Beatdown deck, you must also include 'Splash Anti-Air' (Baby Dragon, Electro Dragon, Executioner).
The DangerHow to Defend ItThe Lava Hound (Massive flying tank)Ignore it initially; focus all anti-air on the support troops behind it, then clear the 'pups' when it popsThe Inferno Dragon (Escalating beam damage)Use an Electro Wizard or Zap spell to constantly stun it and reset its damage beam to zero Total Coverage
A deck with weak anti-air is a fundamentally flawed deck, regardless of how strong its ground game is.

When the shadow of a Balloon falls across your tower, you must be ready.

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