The New Tetris, and games with Square Tetris mode, like Tetris Worlds, reward the player for creating 4x4 block squares out of four tetrominoes. Building wide platforms (flat top sides) into the top of a square in progress allows more than one such square to be built at once, keeping options open for handling any tetromino.
The New Tetris was developed prior to the standardization of tetromino colors. The diagrams below, like most other diagrams in Tetriswiki, use Tetris Worlds colors per the more recent Tetris Guideline.
Spiral J monosquare
It is best to build J and L monosquares using this spiral method so that platform width is maximised as early as possible.
L on the left and J on the right require a double slide. L on the right and J on the left require a double slide if there isn't enough support below. See below.
Spiral L monosquare
Non-spiral L and J monosquares
One side of each of the spiral monosquares depicted above requires a double slide.
These squares are built on the same side and do not require a double slide if built on top of a 3-block platform.
Building a T monosquare quickly
If three T pieces are readily available and there is only a platform one block wide upon which to build, it is wise to build in a slightly different way:
If two of the same 2×4 constructions are put together, monosquares are formed. Alternatively, two different 2×4s can be put together (or one sandwiched between two I pieces) to make multisquares in addition to those below.
Most of these multisquares can be constructed in different rotations, with the pieces being added in different orders or with an I piece on the opposite side. The following are some of the most efficient ways of building them.
SJSJ and ZLZL
JSSJ and LZZL
ZLLZ and SJJS
This is possible in The New Tetris but relies on uncommon wall kicks: see tactical rotation.
ZLTT and SJTT
STTJ and ZTTL
TZTJ and TSTL
TTLZ and TTJS
This requires the same move as for the ZLLZ and SJJS multisquares, and is good to fall back on in the middle of building a T monosquare.
LTZT and JTST
LTTI and JTTI
TTLI and TTJI
Similarly to TTLZ and TTJS, good to fall back on when a T monosquare is abandoned.
ZLJI and SJLI
JSLI and LZJI
LJZI and JLSI
This requires the same move as the ZLLZ and SJJS multisquares. It is of course best built with the I on the other side if the I, J/L and Z/S are available already
LSIL and JZIJ
Requiring double slide (or tactical rotation)
With I before S or Z (triple slide or tactical rotation in addition to the moves above):
IJLO and ILJO
As with many of these multisquares, the I can be on the other side and added last if the other pieces are all available already.
JJOI and LLOI
Good to fall back on midway into a spiral L or J monosquare.
In some cases a piece must be moved sideways two or more spaces before dropping at all. The New Tetris's smooth tetromino falling animation often means this can't be done – pieces can't be moved to sit on a ledge too far under an overhang. There are methods to get around this: tactical rotation.