Rhythm Game Charting & Level Design
Discover the art and science of mapping music to gameplay.
Ever wondered how your favorite songs get turned into playable levels? "Charting" (or beatmapping) is the process of placing notes, holds, and obstacles in sync with a musical track. A good chart makes you feel like you are performing the music; a bad chart feels like a random button-mashing test. Here is a look behind the curtain at how rhythm game levels are designed.
1. The Foundation: BPM and Timing
Before a single note is placed, the "charter" must establish the foundation of the song.
- BPM (Beats Per Minute): Finding the exact tempo of the song. If the BPM is off by even 0.01, the notes will gradually drift out of sync with the music over the course of the track.
- Offset: Finding the exact millisecond the first beat of the song begins.
- Time Signatures: Understanding if the song is in 4/4, 3/4, or something more complex, which dictates where the major downbeats fall.
2. Note Density and Difficulty
How many notes should be on the screen? This determines the difficulty level.
- Easy/Normal: Usually maps to the primary melody or the strong drum beats (quarter notes or half notes).
- Hard/Expert: Maps to faster melodies, hi-hats, and introduces 8th and 16th notes.
- Extreme/Master: Maps almost every distinct sound in the music, utilizing 16th streams, 24th note bursts, and complex polyrhythms.
3. Pattern Design
A chart is made of patterns. Good charters use patterns to reflect the feeling of the music.
- Jacks/Trills: Rapidly pressing the same button or alternating between two buttons. Often used for drum rolls or fast synth arpeggios.
- Stairs/Streams: A rolling sequence of notes (e.g., 1-2-3-4). Used for sweeping piano or guitar scales.
- Chords: Pressing multiple buttons at once. Usually placed on heavy impacts like crash cymbals, bass drops, or loud synth chords.
4. Playability and "Flow"
The most subjective part of charting is ensuring the level "flows" well. This means the physical movements required by the player should feel natural and ergonomic.
- Avoiding "Hand-Breaking" Patterns: While a song might technically have a sequence of sounds, forcing a player to twist their hand into an uncomfortable position is bad design. A good charter adapts the music to fit the physical constraints of the controller.
- Visual Clarity: Notes shouldn't obscure each other. The player needs to be able to read what is coming next.
5. The Difficulty Curve
A well-designed chart tells a story through gameplay. It shouldn't be the same intensity from start to finish.
- The Intro: Introduces the core patterns of the song.
- The Build-up: Gradually increases note density.
- The Chorus/Drop (The Kiai Time): The climax of the chart. The highest density of notes, the most complex patterns, and the highest visual intensity.
- The Outro: A cool-down period allowing the player to recover.