When an object, such as an enemy or a destructible part of a room such as a crate, is destroyed, it has the chance to produce an item drop. Item drops consist of anything from health pickups, to missile refills, to Power Bomb drops. In all three Prime games, there is an element of randomness to what drops you get, but how the game decides which drops you get varies between games.
In Prime 1, drops are determined based on the individual room. In each room, there is a set percentage for how likely you are to get certain items over others. For example, in Sun Tower Access, you will almost always get at least one Ultra energy drop, if not two, when destroying the crates in the room.
Metroid Prime 2: Echoes
In Echoes, drops occur based on what Samus has. The game performs a series of checks when spawning drops, in the following order:
- If Samus' energy is below 20%, Ultra energy drops have a 75% chance of spawning
- If Samus has no missiles, and her missile capacity is more than 10, missile drops have an 80% chance of spawning
- If Samus has Power Bombs and has 0 PBs, Power Bomb drops have an 80% chance of spawning
- If Samus' energy is below 50%, Large energy drops have a 50% chance of spawning
- If Samus' energy is below 75%, Medium energy drops have a 30% chance of spawning
- If Samus can get extra missiles, missile drops have a 30% chance of spawning
- If Samus can get extra energy, Small energy drops have a 60% chance of spawning
- If Samus can get extra Power Bombs and has more than 0 PBs, power bomb drops have a 20% chance of spawning
Worth noting is that even in the most extreme cases, such as when Samus' health is below 20%, there is still a chance that the game doesn't drop anything. This can kill runs if the player gets especially unlucky, especially when traversing the Dark Aether without the Dark Suit or Light Suit.
Metroid Prime 3: Corruption
- RNG - Influences what drops you get