Editing Field map encounter mechanics (section)

=== Manipulating Formations ===

As you might have been able to guess, a similar method is used to generate the random numbers used for formations as the method used for danger thresholds, however it’s even simpler this time. A different random index is used for formation generation, making it independent from danger threshold generation. The index that determines what encounters you get is a 1-byte value called the Formation Accumulator, or just formation for short. When this generator calls for a random number, formation is incremented by one, then the RNG table value at the index of the new formation value is returned and is used as the random value.

This generator returns a value between 0 and 255, so to get a value between 0 and 63, it is divided by 4 and truncated to an integer.

Formation RNG is called once to determine if this encounter is a special formation. If it isn’t, it’s called a second time to determine what this encounter’s formation is. If a reroll is needed, it’s called a third time. As a result, the formation value can advance by 1, 2, or 3 depending on the current state of the formation value and the last encounter formation, which is what determines when a reroll occurs.

Formations can be manipulated by skipping or not skipping certain encounters to cause formation to increase or not increase at specific points. It can also be affected by getting encounters on certain fields, depending on if they have a special encounter table or not, or if their encounter table results in a reroll. This reroll is also known as a “bump” or “getting bumped”, since you’re bumped past an encounter to the next, or bumped past the usual formation increase of 2 and up to 3.

For example, you can intentionally waste movement and force an encounter at the end of a field instead of going to the next field, even if it was possible to make it to the next field, just because getting an encounter on the first field would result in a different and possibly more favorable enemy formation or formation increase than getting it on the second field. You can also intentionally avoid walking under an encounter that could be skipped because getting that encounter at that point would result in a more favorable formation increase.

In general, formation manipulation is needed to ensure getting specific encounters, such as those that give Enemy Skills such as Death Claws for Laser or a Boundfat for Death Sentence, or to avoid getting particularly bad encounters, such as pincers. However, formations are in general more difficult to manipulate since you don’t have much flexibility or control over their increase, but just knowing what formations you will get is often enough to prepare for a particularly bad encounter formation if one were to occur. Formation manipulation and routing is especially important in 100% because the category requires many drops, steals, morphs, enemy skills, and even kills from specific enemies all over the game.