9 Kings: How to Beat King Difficulty with Castle Attacks Only

To beat King difficulty in 9 Kings using only Castle attacks, you must turn your stronghold into your sole offensive tool while completely banning attacking troops and combat installations from your deck. Success depends on funneling incoming swarms through reinforced walls, prioritizing Castle attack speed and projectile count, and funding shop rerolls through an early non-combat economy.

Challenge Rules and Drafting Restrictions

This challenge restricts all combat damage exclusively to the central Castle across all nine campaign years.

Banned offensive units: Never draft or place frontline soldiers, spearmen, archers, or offensive wizards. Any deployed unit that inflicts damage immediately breaks the challenge conditions.
Banned offensive structures: Skip combat towers such as Autocannons, Spires, and Ballistas.
Allowed cards: Draft only passive Castle stat buffs, non-attacking barrier walls, structural sustain perks, and economy generators.

If a draft pack contains only offensive cards, pay the reroll fee or skip the selection entirely to keep your deck free of damage-dealing units.

Castle Stat Priorities

At baseline, the Castle fires a single projectile at a moderate pace, which cannot keep up with King difficulty wave density. Prioritize your upgrades in the following order:

Attack speed: Stacking fire rate prevents swarms from stacking up against your inner defenses.
Multi-target and projectile count: Secure piercing projectiles, bouncing attacks, or multi-shot perks so each volley clears multiple enemies.
Range extensions: Increasing range allows the Castle to engage targets the moment they enter the grid, widening your damage window.
Flat attack power: Upgrade raw damage only after securing attack speed and multi-target coverage.

Investing purely in flat damage causes the Castle to overkill single targets while fast skirmishers bypass your perimeter.

Grid Layout and Wall Placement

Walls serve as your main stalling mechanism because the Castle cannot relocate. To ensure enemies remain within range while attacking your barriers, position your defenses deliberately:

Build within the inner two rings: Keep defensive walls inside the Castle's primary firing radius. Placing walls along the outer board edges allows hostile ranged units and siege breakers to destroy them outside your Castle's reach.
Layer two to three barrier ranks: Surround your core base with layered walls so your defenses remain intact if an outer barrier falls.
Create choke points: Leave narrow gaps in outer barrier layers to funnel approaching troops into tightly packed lanes. Clustering incoming enemies maximizes the value of bouncing and multi-target Castle projectiles.

Card Drafting and Economy Management

Ignoring unit recruitment leaves you free to channel all starting gold into economy structures during Years 1 through 3. Establishing an early economic baseline ensures you have enough gold to reroll for high-tier Castle perks and repair ruined barricades in later years.

Card Category	Priority	Strategic Function	Target Cards
Castle Enhancements	Critical	Increases fire rate, range, and target count	Attack Speed, Multi-Shot, Firing Range
Defensive Barriers	High	Traps hostile waves inside Castle firing range	Stone Walls, Reinforced Barricades, Fortifications
Economy Structures	Moderate to High (Early)	Generates gold for shop rerolls and upgrades	Farms, Shrines, Gold Generating Passives
Banned Cards	Zero (Always Skip)	Invalidates the challenge run	Soldiers, Archers, Ballistas, Damage Spells

Year-by-Year Campaign Progression

Pacing your card drafts across the nine-year campaign determines whether your Castle can withstand the final boss encounter.

Years 1–3: Establishing the Base

The Castle's low initial attack speed creates significant vulnerability against split waves. Place basic walls directly adjacent to your stronghold to funnel early attackers into single-file paths. Secure Farms or Shrines early, but avoid aggressive rerolling until your Castle's basic firing speed can reliably handle standard waves.

Years 4–7: Countering Advanced Waves

Mid-game waves introduce shielded units, high-health champions, and ranged threats. Shift your investment into projectile duplication, bouncing shots, and wall regeneration perks. Reinforce your choke points with secondary barrier layers to keep champions trapped under continuous Castle fire.

Years 8–9: The Final King Encounter

The Year 9 King boss brings massive health pools and destructive area-of-effect damage that can flatten single-layer walls quickly. Defeating the final monarch requires pre-building redundant defensive layers and stacking attack speed perks until the Castle outputs continuous barrages, burning down the boss before your inner barrier line collapses.