You want a mode that keeps the players guessing but still rewards skill. Start with a core mechanic that never changes—like movement or a resource. Then overlay random modifiers that trigger every few rounds: gravity shifts, enemy spawn rules, or a new objective that appears on the map. The hidden roadmap comes from patterns you plant: a sequence of “shift events” that repeat every cycle, and if you learn that cycle, you can time your moves. Keep the shifts subtle enough that players notice a pattern but not so obvious that everyone just copies it. That’s the sweet spot between chaos and precision.