
Procedural Level Generation: scaling puzzles with algorithms
Why we built a generator instead of handcrafting every level.
Joel D.
Founder, Lemon Tree Studio
When we started our puzzle slider game, we faced a key decision: handcraft every level or build a system to generate them. After prototyping both approaches, we invested in procedural generation.
The trade off was clear. Handcrafting provides precise control, but it costs time and limits scale. A generator requires upfront work, but it can produce endless, balanced puzzles and free the team to focus on polish and core mechanics.

Building the generator was iterative. We sketched the algorithm, implemented a rough prototype to test constraints, and tuned a scoring function to ensure levels were solvable and varied. That scoring function became the heart of the system.
Benefits we saw
- Scale: produce thousands of levels without manual design work
- Replayability: generate new but balanced challenges on each play
- Faster iteration: tune generation parameters rather than redesign levels
- Focus: designers and artists concentrate on high impact polish
The system took time to refine, especially the balance between randomness and solvability. We added constraints, playability checks, and a rejection sampling step to filter weak levels. Over time the generator produced levels that matched our difficulty curve and produced engaging short play sessions.
Practical advice for teams
- Start with a simple scoring function to rank candidate levels
- Build small prototypes to validate constraints quickly
- Log generation failures to iteratively improve rules
- Provide designers with parameter presets for targeted control
In our project procedural generation was not a silver bullet, but it became the most effective way to deliver a large, replayable puzzle set without months of manual level design. If your game benefits from variety and replay, consider investing in a generator early.

