Units are the board. Knowing the role is what makes gold count.
The roles
Melee units hold the front and take the hits. Ranged and magic units deal damage from behind them. Support units change how the board performs. A board of one role breaks.
Read before you buy
An expensive unit that covers a lane you already hold is wasted gold. Buy the role the next wave needs at the tier you can afford. The unit database shows both.
Coverage first
Cover every lane before you upgrade a single unit. A maxed unit on one lane and a hole on another is a run that ends at the hole. Spread, then deepen.
Tier matters
Higher tiers hit harder and often reach further. But a tier-one unit on the right lane clears more than a tier-three unit in the wrong spot. Role and placement beat tier.
The merge guide covers how to grow a unit you already have instead of buying a new one.
Know the role before you buy
Each bonker is a role: tank (front, soaks hits), dps (back, deals damage), support (buffs or heals), economy (generates gold). A board needs at least one tank and one dps per lane; support and economy are force multipliers on top. Buying a second dps when you have no tank just means a dead dps — read the role before spending.
Grow, don’t multiply purchases
When you already hold a bonker, the next copy should merge, not sit beside it. The merge guide covers how to grow a unit you have instead of buying a new role you cannot yet pair. A unit guide is your checklist: confirm the role you lack, then buy only that, so every gold coin builds the board.