(Values obtained from the PS2 version of the game, on Pro difficulty. Some of the values are different when playing on Normal or Easy difficulties.)
Resident Evil 4 is quite generous with ammo. It not only provides you with ammo from fixed-locations, but once you buy/find a weapon, it will start giving you ammo for it via random-sources as well. Random drops will stop once you reach the following limits:
|Type of Ammo/Item||Limit (# of rounds)||Drop-Probability|
|Magnum||No Limit||very low|
|Grenades||No Limit||very low|
Random Sources refer to enemy-drops and random containers. Whenever you kill a regular enemy or break a random box/barrel/vase/etc., you will randomly get either:
- A random amount of pesetas
- A random brick of ammo
- A random type of Grenade
- A Green-Herb
- Nothing at all
Random Sources differ from Fixed-Locations in that the latter are not random; their placements, type of item, and quantities were put as a fixed value by the programers and cannot be influenced by the player.
Random sources, on the other hand, are influenced by the items you carry in your inventory. There are 3 kinds of items that will in turn influence the kind of items you will get from a random source (the item inside a random container or dropped by an enemy is determined at the moment of breakage/killing):
- Which weapons you're carrying: You will only get random TMP ammo if you actually carry a TMP in your inventory. The same is true for shotgun, rifle, magnum, mine-darts, and Handcannon ammo. (Handgun-ammo is an exception; it will be explained later.)
- The amount of a particular type of ammo you carry: As seen on the table above, the game will stop giving you random-ammo of a particular type whenever you reach the limit for that type of ammo. For example, the limit for TMP ammo is 200 rounds, so that means that the game will completely stop giving you TMP ammo from random sources whenever you are carrying 200 or more TMP bullets. (Although you will still find TMP-ammo from fixed-locations.)
- Whether you are carrying at least 1 green-herb or 1 first-aid-spray: The game will randomly give you a green-herb from random sources whenever you're are not carrying at least 1 green-herb or 1 first-aid-spray in your inventory.
Limits for each kind of ammo
The ammo inside the weapon's magazine does count towards the ammo-limit, so for example, the 200 round limit for TMP ammo will be reached if you are carrying 100 rounds inside the TMP itself, plus one ammo-brick of 100 extra rounds. Let's say you then decide to fire one TMP round (so you're now carrying 199 rounds), then the game will once again start giving you TMP ammo from random sources until you reach the 200 limit again. This doesn't mean that you're guaranteed to get TMP ammo as soon as you fall bellow the 200 limit; it merely means that TMP ammo will enter the "rotation" of random items that the game will possibly give to you the next time you encounter a random source.
* Handgun ammo is a special case. Unlike the other types of ammo, the game will provide you with handgun-ammo from random sources even if you don't carry a handgun. As seen before, for all other types of ammo, the game will only give them to you if you actually carry a weapon that can use said type of ammo, but that's not the case for handgun-ammo.
Handgun-ammo behavior gets even stranger, as the 70-round limit only applies when you carry at least one of the following types of weapons in your inventory: shotgun, rifle, TMP, magnum, Mine-Thrower, and Handcannon. If you don't carry any of these weapons, then random handgun-ammo has no-limit: the game will keep giving you handgun-ammo, no matter how much you're carrying already.
In order to further clarify the concepts:
- The limit for handgun-ammo is 70-rounds whenever you carry one or more of the following weapons in your inventory:
- a shotgun
- a rifle
- a magnum
- Handgun-ammo has NO-limit whenever you don't carry one or more of the aforementioned weapons. This case can arise if, for example:
- Your inventory is empty
- You only carry grenades in your inventory
- You only carry a handgun in your inventory
- You only carry a handgun, grenades, a Rocket-Launcher, P.R.L., and some healing items
Other Ammo with No-Limit
As seen on the table, some types of ammo (Rifle, Magnum, and Handcannon) don't have a limit. Random sources will keep giving you these kinds of ammo no matter how much of it you already have (provided you carry a weapon of such type in your inventory). The downside being that the drop-probability of these types of ammo is not very high (especially magnum-ammo).
In addition to ammo and money, random sources will also sometimes (quite rarely) give you a Grenade, of any type. The drop probability of grenades is comparable to that of magnum ammo, due to its extremely low occurrence. Grenade drops don't have a limit and they will continue to happen (however rarely) regardless of the contents of your inventory.
The game will randomly give you green-herbs (but never red or yellow) from random sources whenever you carry less than either 1 green-herb or 1 first-aid-spray in your inventory. The drop-probability of green-herbs is quite high and comparable to that of handgun-ammo.
Other healing items, like Eggs, Fish, and Red & Yellow herbs don't count towards the limit. That is, the game will still provide you with green-herbs from random sources even if your whole inventory is filled with eggs, red herbs, yellow herbs, and fish.
*Note*: Random red-herb and first-aid drops can happen, but only when playing on Normal or Easy difficulties, and only when the adaptive difficulty is at the lowest settings.
Ways of applying this knowledge
The idea of knowing all these limits is to trick the game into giving you more of the items you want and less (or none) of the items you don't want. For example:
When you're running low on ammo
As said before, the item inside random containers is determined at the moment of breakage, so if for instance, you're low on shotgun-ammo (say, you only have 24 shells) and you enter a room with some random containers, then you should break all the containers first and then pick up the items. This is because, as long as you carry less than the 25-shell limit, there is a real possibility of a shotgun-ammo brick appearing when you break a random container. But as soon as you pick up a shotgun-ammo brick, it will put you above the 25-shell limit, and all the random-containers you break while at or over the 25-shell limit are guaranteed to not be shotgun-ammo.
The game's infatuation with handgun-ammo is helpful when doing a handgun-only run, because handgun-ammo has no limit while you only carry a handgun.
The game's infatuation with handgun-ammo is a annoying if you don't like handguns or simply prefer carrying a TMP instead (using it in place of a handgun). If this is the case, you surely don't need any of the handgun-ammo the game likes showering you with. Fortunately, there's a workaround to this issue: Always carry at least 70 rounds of handgun-ammo in your inventory.
It's not a perfect solution, because the 2 bricks of handgun ammo will take up 4 spaces in your inventory, but at least, random handgun-ammo drops will completely stop. This has the added benefit of increasing the probability of money drops, which will get you more income than what you would get for selling the handgun ammo drops, so you'll accumulate cash faster.
It could be the case that you want to do a, say, Rifle-Only run, but you first want to do a pre-run playthrough in which your aim is to collect as much rifle ammo as possible. The easiest way to achieve this is to carry:
- Any infinite ammo weapon (Chicago Typewriter, Handcannon, Infinite Rocket Launcher, P.R.L.) to kill everyone easily.
- A Bolt-Action Rifle to make rifle-ammo drop.
- At least 70 handgun rounds in order to stop random handgun-ammo drops.
- At least 1 green-herb or 1 first-aid spray in order to stop random green-herb drops.