Random Encounters in Final Fantasy 1 GBA

First, you need a little bit of background. Final Fantasy assigns a “Battle Region” to your position, based on your location on the overworld map, or which dungeon labyrinth your party is exploring. Each region has eight battle configurations defined. Final Fantasy rolls a number between 0×01 and 0×40 (1 — 64), and based on this random number decides which monsters jump your hapless characters (this is defined in a Battle Record).

Random Battle Chances table

This is the table that defines what our random number between 1 — 64 means.

Table location: 0×2170a0 — 0×2170df.

Data structure size: 64 bytes.

In stock FF1, this is what the table looks like:

0×2170a0 — 00 00 00 00 00 00 00 00 00 00 00 00 01 01 01 01
0×2170b0 — 01 01 01 01 01 01 01 01 02 02 02 02 02 02 02 02
0×2170c0 — 02 02 02 02 03 03 03 03 03 03 03 03 03 03 03 03
0×2170d0 — 04 04 04 04 04 04 05 05 05 05 05 05 06 06 06 07

What do these values mean? Each byte has a value between 00 and 07. If you count the instances of each value, we arrive at this:

• 00 — 12 instances

• 01 — 12 instances

• 02 — 12 instances

• 03 — 12 instances

• 04 — 6 instances

• 05 — 6 instances

• 06 — 3 instances

• 07 — 1 instance

So, battle #1 through #4 show up 12/64 of the time on average. Battles #5 and #6 show up 6/64 of the time on average. Battle #7 shows up show up 3/64 of the time, and battle #8 is quite rare… it has only a 1/64 chance of showing up.