How to Defend Three Portals in Portal Defense Chapter 1-6

To complete Chapter 1-6 in Portal Defense, build your main towers at central intersections where paths from multiple enemy portals overlap, and maintain a gold reserve between waves to maximize your end-of-round interest earnings.

Positioning Towers for Multi-Portal Coverage

Chapter 1-6 introduces three active enemy spawn portals. Investing heavily in a single lane leaves other paths exposed to fast leaks, so your layout must emphasize multi-directional coverage.

• Target Central Intersections: Position primary towers at central hub junctions or high-ground spots where their range reaches enemies coming from at least two portals.
• Intercept Enemies Early: Set up defenses near path convergence points rather than near the end of the track to allow extra time to catch leaking units.
• Add Dedicated Single-Target Units: If a specific portal spawns particularly tough or high-health enemies, place a dedicated single-target tower along that specific lane to soften targets before they reach the main hub.

Managing Gold and Earning Interest

Interest in Portal Defense is calculated at the end of each round based on your unspent gold balance. Spending all available gold immediately starves your mid-stage economy and prevents you from affording necessary high-tier upgrades later.

1. Maintain Interest Thresholds: Keep your floating gold balance above the minimum required for interest yields at the end of every wave.
2. Spend Reactively: Purchase new towers or upgrades only when incoming enemy compositions pose a genuine threat to your current defensive line.
3. Prioritize Area-of-Effect Damage: Build crowd-control and area-of-effect (AOE) towers first, as multi-target damage offers a better return on gold when managing three active lanes.

Upgrading Structures and Adapting to Wave Types

As wave density increases, upgrading existing structures is more cost-effective than filling empty spaces with basic towers. Higher-tier upgrades improve your damage-per-gold ratio without cluttering valuable placement real estate.

Focus upgrade gold on support towers that deal slow effects or armor reduction. Amplifying the damage of existing central towers allows your primary damage dealers to handle larger waves across all three lanes.

Check upcoming wave previews before each round starts. If a wave features fast or resistant enemy types that bypass your current setup, sell underperforming or poorly positioned towers to recoup gold and relocate your defenses to match the incoming threat.