Day 16: Building a State Machine in Godot | Tower Defense Devlog

Day 16 of my 60-day challenge to learn the Godot game engine (focused on 2D).

Yesterday (Day 15) I spent a lot of time watching and studying state machines, and today I implemented a basic state machine in my tower defense project to explore best practices and learn how to structure state-driven logic in Godot.

In this video, I cover:
• What a state machine is and why game dev uses them
• Applying state concepts to towers (Idle vs Attacking)
• Managing transitions when targets enter/leave range
• Handling “invalid target” edge cases (target destroyed by another tower)
• Using timers for fire rate and state-controlled behavior
• Building a reusable State base class (enter/exit/update/physics_update)
• Implementing a simple StateMachine to switch between states
• “Children run before parents” in _ready and how that impacts setup
• Fixing a currency reset bug caused by global state

I’m being honest here: the state machine feels like extra overhead for this specific tower behavior right now, but the learning value is huge — and I want to figure out how to make state machines truly earn their place in my architecture (likely by expanding into richer states like reload/ready/attack).

Next up: making state usage more meaningful, adding waves/progression, and continuing to tighten the tower defense systems.

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Feedback and ideas are always welcome