cambridge/docs/rulesets.md

Rulesets

A ruleset is a set of rules that apply to any game mode.

A ruleset consists of the following things:

• A rotation system, which defines how pieces move and rotate.
• A lock delay reset system, which defines how pieces lock when they can no longer move or rotate.

If you're used to Nullpomino, you may notice a few things missing from that definition. For example, piece previews, hold queues, and randomizers have been moved to being game-specific rules, rather than rules that are changeable with the ruleset you use. Soft and hard drop behaviour is also game-specific now, so that times can be more plausibly compared across rulesets.

Rotation system

A rotation system defines the following things:

• The block offsets of each piece orientation.
• The wall or floor kicks that will be attempted for each type of rotation.

There are three main classes/families of rotation systems:

• ARIKA, commonly known as ARS.
  • ARIKA-CLASSIC, commonly known as Classic ARS.
  • ARIKA-TI, commonly known as Ti-ARS, or "ARS with floorkicks".
• STANDARD, commonly known as SRS.
  • STANDARD, or normal SRS.
  • STANDARD-EXP, known as SRS-X in its original Heboris incarnation.
  • STANDARD-WORLD, known as World Rule in TGM3.
• CLASSIC, commonly known as ORS or NRS (Nintendo). Also houses some traditional rotation systems.
  • CLASSIC-1989, the no-wallkick system used by NES Tetris.
  • CLASSIC-1984, the Electonika-60 system, where the I piece is one space higher than in CLASSIC-1989.
  • CLASSIC-SEGA, the original Sega rotation system that spawned Arika.
  • CLASSIC-TENGEN, the weird one with orientation problems.