From Hard Drop Tetris Wiki

Jump to: navigation, search


Developer(s) Damian Yerrick
Publisher(s) Pin Eight
Release Date(s) 2006
Version 0.45 released April 2008
Platform(s) Allegro (binaries exist for Windows and Mac, and source compiles on Linux); Game Boy Advance; Nintendo DS

Gameplay Info

Next pieces 1-8
Playfield dimensions Selectable; default 10w x 24h with 20h ceiling
Hold piece Yes, with IHS
Hard drop Yes, both "firm" and "hard" variants
Rotation system Selectable: SRS, TGM rotation, others
Has 180 rotation {{{180}}}
Adjustable tuning {{{tuning}}}
Garbage attack type {{{garbage}}}
Garbage blocking type {{{blocking}}}
Website {{{website}}}
Lockjaw title.png LJ 0.18 play.png
"Lockjaw looks fun as hell."
-- Kris, Cyanide and Happiness #1817

Lockjaw is a highly customizable open-source fan game. The overall idea of its customizability was inspired by one of Henk Rogers' interviews. Lockjaw's customizability allows it to simulate other tetromino games such as Tetris The GrandMaster Series and Tetris DS. As of June 21st 2012, LockJaw is no longer available for download due to a court ruling.[1][2]



Although Lockjaw is developed to appease tetris fans, it also satirizes the current state of Tetris. The original set of planned modes, meant to poke fun at Tetris DS,[3] included:

  • Dual Marathon - The keys control both a platform game (in the top window) and standard singleplayer tetris (in the bottom screen). If you die on either window, you lose.
  • Ridin' Spinners - This mode exhibits standard singleplayer tetris gameplay. However, if you abuse lock delay or if you perform a T-Spin Triple twist, the music changes to "Ridin' Spinners" by Three 6 Mafia for a few seconds, and the screen spins (as in Lockjaw: The Overdose).
  • Low Rider - This mode exhibits standard tetris gameplay, except the visible playfield is 8 rows tall (instead of 20). Implemented, as "Well height" option.
  • Vs. - This mode exhibits standard singleplayer tetris gameplay. However, when you receive an I tetromino (after the first), you also receive four lines of garbage. Implemented, as "Garbage" option.
  • Items - 3/4 of the time you start the mode, it will play annoying music for 2 minutes, give an 86420 error, and quit. The rest of the time, it will play annoying music between 15 seconds and 2 minutes and then behave like standard single player tetris. However, you will recieve random starting orientations, no rotation, and hidden next pieces. The speed starts at 1G. Every time you are given an I piece, you will either receive four lines of garbage or be the target of a banana item. Implemented partially.
  • Beyond Level 20 - The music starts slow, 60 beats per minute. On every beat, the tetromino hard drops. Every time you clear 30 lines, the music speeds up by 10 BPM. Think of it as Shirase mode, DDR style. Implemented, as "Rhythm" speed curve.


Since version 0.01, Lockjaw has been factory-set to its own speed curve, called "Exponential". Versions 0.01 through 0.44 behaves as follows, if n pieces have come out:

Number of pieces Gravity Lock delay
0 ≤ n < 609 1/60G * (259/256)^n 40 frames
n ≥ 609 20G 40/(1 + 3/256 * (n - 609)) frames

Version 0.45 changed Exponential to remove the repeated multiplication by 259/256. Instead, it approximates the curve as a stepwise function over 30-piece sections, doubling gravity precisely every 60 pieces.

In addition, Lockjaw can emulate a few other games' speed curves, controlling ARE, gravity, DAS delay, lock delay, and line clear delay.


Since version 0.01, Lockjaw has been factory-set to its own scoring system. It involves computing the garbage like Tetris DS standard vs. does, then awarding 100 points for each line clear and 200 for each row of garbage.

  • Single: 100 (1L)
  • Double: 400 (2L + 1G)
  • Triple: 700 (3L + 2G)
  • Home run: 1200 (4L + 4G)
  • T-spin: 500 (1L + 2G) per line
  • Back-to-back home run or T-spin: 200 (1G) more

(A "home run" is four lines cleared with one piece, called a "tetris" in products of The Tetris Company. A line clear is "back-to-back" if the line clear before it was a home-run or a T-spin.)

In addition, Lockjaw can emulate a few other games' scoring formulas.

External links

This article is a Hard Drop Tetris Wiki stub.

You can help Hard Drop Tetris Wiki by expanding it.

Damian Yerrick's falling block games
Carbon Engine: freepuzzlearena (1999–2000) | Lockjaw: The Overdose (2000–2006)
Lockjaw Engine: Lockjaw (2006–2008+)
Other: Luminesweeper (2005) | LJ65 (2003-2009)