Jstris
Release Information
Developer	jezevec10
Publisher
Platform	JavaScript
Release Date	6 Dec 2014
Gameplay Information
Next pieces	5
Playfield dimensions	10x20
Rotation system	SRS, ARS, C2, O-spin
Hold piece	✓
Hard drop	✓
Has 180° rotation	✓
Adjustable tuning	✓
Websites

Jstris is a JavaScript based browser game. This game was created on December 6, 2014.

Gameplay

Jstris uses modern guideline rules: Bag Randomizer, Hold feature, 5 Previews, SRS rotation system including kicks, Lock delay. Controls are customizable, including the block skins and DAS. The sound effects can be toggled, with the selectable sound packs being NullpoMino, Yotipo and Rainforest. There are seven rooms: the 1v1 room, bot 1v1, bot room, map room, default room, slow room, and team room.

Modes

These modes can be selected by selecting each mode from the Play drop-down menu on the top bar.

• Live: This is a multiplayer mode where multiple players can battle against each other, send garbage, and the last player standing wins.
• Cheese: In Cheese, one player must clear all of the garbage lines as fast as possible. The number of lines to clear is selectable from 10, 18, and 100 lines. An infinite option is availabe, but there is no leaderboard for the infinite cheese race mode.
• Survival: In Survival, the player must survive for as long as they can while garbage lines rise at a rate of 1 line per second
• Sprint: The player is given a choice to clear 20, 40, 100, or 1,000 lines in the fastest time.
• Map Downstack: Players will need to clear all the map blocks and/or get a PC finish depending on the settings the map has.
• Ultra: The player has 2 minutes to get the highest score.
• Free Play (Also known as Practice in the drop-down menu): A training mode.

Additionally, special rulesets can be applied:

• Big Mode: All pieces are quadrupled in size, mimicking playing in a 5 × 10 field. Line clears are checked like they would be on a normal board, however. In this ruleset, the player can only play 40/100/1000 line Sprint and Free Play.
• Pentomino: All pieces become pentominoes. In this ruleset, the player can play all Sprint modes, 10-line or infinite Cheese Race, Ultra and Free Play.
• MPH: No previews nor Hold are available, and the randomizer is set to "Classic" (which is actually memoryless). In this ruleset, the player can play all Sprint modes, all Cheese Race modes, Ultra, 20TSD, PC Mode and Free Play.

Details

Attack and combo table

Jstris' attack and combo table is nearly identical to that of Tetris Friends in Expert+ mode:

Attack table Action Lines sent Single 0 Double 1 Triple 2 Quadruple (Jstris) 4 Quintuple or higher 6 T-Spin Single 2 T-Spin Double 4 T-Spin Triple 6 Mini T-Spin Single 0 Spin Quadruple or higher 7 Perfect Clear 10 Back-to-Back Bonus +1

Combo table Combo Lines sent 0 +0 1 +0 2 +1 3 +1 4 +1 5 +2 6 +2 7 +3 8 +3 9 +4 10 +4 11 +4 12+ +5

Mini T-spin Doubles count as T-spin Doubles, thus sending 4 lines of garbage.

Scoring

Jstris scoring matches that of guideline games, with a notable exception being the Perfect Clear.

Scoring

Action	Score
Single	100
Double	300
Triple	500
Quadruple (Jstris)	800
Quintuple or higher	1600
T-Spin	400
T-Spin Single	800
T-Spin Double	1200
T-Spin Triple	1600
Mini T-Spin	100
Mini T-Spin Single	200
Spin Quadruple or higher	1600
Perfect Clear	+3000
Back-to-Back Bonus	+50% to difficult line clears
Combos	+(50 * current combo)

Mini T-spin Doubles count as T-spin Doubles, thus scoring 1200 points.

Notes

Buffer zone

Above the board, Jstris uses a single-row buffer zone, extending the effective height of the playfield from 20 to 21. Blocks that are in row 21 will reappear on the board once stack gets lowered. However, rows 22 and above are not a part of the buffer zone, meaning that blocks in such rows will vanish and won't reappear after the stack gets lowered. Jstris' buffer zone is also not solid, so pieces won't collide with blocks in buffer zone. This can be taken advantage of in some modes, such as 20TSD:

S piece is active	S piece locked - the block above row 21 vanished	L piece is active. Note that it overlaps the part of the S piece.	L piece locked

Pentominoes

The 4 rotation states of all pentominoes in Jstris, listed in clockwise order. The black squares with yellow squares inside help to illustrate the rotation centers, and do not appear in-game.

Pentominoes in Jstris follow the Super Rotation System kick table:

• I5 piece uses the SRS kick table for the I-piece,
• Every other pentomino uses the SRS kick table for Z, S, L, J and T-pieces.

This notably causes some off-the-wall kicks to fail:

Attempt to rotate R → 0	Test 1	Test 2
Test 3	Test 4	Test 5 All tests failed

O-spin

O-spin is a meme rotation system in which O-spin Triples and O-spin Quadruples are possible. It also allows for many unconventional spins, because its kick table contains 15 kicks, as opposed to SRS which only contains 4 kicks.

Wall Kick Data for O-spin Rotation System

	Test 1	Test 2	Test 3	Test 4	Test 5	Test 6	Test 7	Test 8
Any rotation	( 0, 0)	(-1, 0)	( 1, 0)	( 0,-1)	(-1,-1)	( 1,-1)	(-2, 0)	( 2, 0)
	Test 9	Test 10	Test 11	Test 12	Test 13	Test 14	Test 15	Test 16
Any rotation	( 0,-2)	(-1,-2)	( 1,-2)	( 0, 1)	(-2,-2)	( 2,-2)	(-3,-3)	( 3,-3)

Examples:

	Rotate CW	Passes test 16 T-spin Triple

	Rotate CW	Passes test 10 L-spin Triple

O-pieces however are transformed when rotated in a certain way:

1. O-piece transforms into an L piece and then into a T piece to perform an O-spin Triple. This is a reference to a meme YouTube video, in which a player performs an O-spin Triple in Tetris Friends.. The setup shown below won't work when mirrored.

T-spin Triple setup	Rotate CW	Rotate CW	O-spin Triple

2. The O-piece transforms into a 4 × 4 O-piece to perform an O-spin Quadruple.

	Rotate CCW	O-spin Quadruple

External links

• Play Jstris
• Original forum thread