Battle Garegga/Advanced Rank

Overview

Rank in Battle Garegga is a bounded integer. Its maximum value is 15,728,640, and its minimum value is 2,097,152 for "normal" DIP switch settings and "Arcade" mode in the Battle Garegga Rev.2016 port.

In the arcade release, rank is hidden from the player. However, the Battle Garegga Rev.2016 port allows the player to track rank as a percentage in real time in the "rank graph" M2 gadget. The rank% displayed in the rank graph is a simple linear conversion from the rank variable stored by the game:

rank% = 100 * [(max-rank)/(max-min)],

max = 15,728,640,

min = 2,097,152.

Note that the rank% is 0.0% when rank=max and 100.0% when rank=min. Thus, high rank means low difficulty and vice versa.

For a rank change from any given source, the conversion goes:

Δrank% = 100 * [Δrank / (max - min)]

Rank is updated every frame according to a value called the per-frame rank as well as other specific events. These events are firing the ship's main shot, firing an option, picking up an item, deploying the ship's special weapon, sealing an enemy bullet, and dying.

Frame Rank

The frame rank consists of a base value, a multiplier, and extra additions. It is applied to the rank on every frame during a playthrough.

The base value depends on the game version and DIP switch difficulty, and is equal to 22 for the "normal" DIP switch on the Japanese arcade release and the "Arcade" mode of the Battle Garegga Rev.2016 port.

The multiplier depends on the maximum autofire rate activated by the player during the current credit, and is applied directly to the base frame rank.

The extra additions are increments of +1 or +2 that are added to the current frame rank when powering up the main shot by collecting a small shot power up or activating a secret power up. They are not affected by the multiplier.

When changing the autofire rate, the new frame rank will be the current frame rank or the product of the base frame rank and the new multiplier, whichever is greater.

References & Contributors

1. ST: Battle Garegga, https://shmups.system11.org/viewtopic.php?f=5&t=351