The Logic Behind Metroidvania Backtracking

In lock-and-key puzzles, it is generally better to show the lock before the key. But what happens when that key is an ability? Unlike a key item, which can be consumed on use, a new ability can be used repeatedly to unlock all locks of a given type. Creating a new ability for every lock is expensive and potentially overwhelming to the player. The Metroidvania genre has a solution so iconic it defines the genre's feel: introduce the same lock many times before the key, then ask the player to backtrack repeatedly.

In Warioland 3, you frequently encounter obstacles you cannot bypass. At the start, all you have is punching and jumping. There are hard blocks you cannot break and blocks above your head you cannot punch. There are rivers you cannot cross because you can't swim. The game constantly teases you with inaccessible areas. Then, you gain a power-up: the ability to punch harder, bash things above you with your head, or swim through water. Now, you recall all the times you encountered a particular obstacle and feel the need to backtrack. This discovery and backtracking is the core loop of every Metroidvania.

Backtracking works so well because of foreshadowing. If a single lock foreshadows a single key, multiple locks amplify the anticipation the player feels. The more impassable rivers you encounter, the more exciting it is to discover the flippers that let you bypass them. Rather than a chore, backtracking adds to the reward of acquiring the flippers, extending it over a longer gameplay period.

Key abilities are powerful but wasted if they don’t have many locks or if their locks are all in the future. When you introduce an ability that functions as a key, make sure the player has encountered the corresponding lock many times already.