Irregular Form

Unlike Regular Form, Irregular Form refers to chains that have a variable structure that may or may not be repeatable into itself. They tend to have a fairly specific use and a much more difficult build-order than Regular-type chains. However, knowing these forms will greatly increase your chaining efficiency because the RNG won't always give you the pieces you want.

L-Shaped Base

Also referred to as DAA (だぁ積み, daatsumi), SMR (スーパーみみかき連鎖, super mimikaki rensa), or Marumekomi (丸め込み), L-Shape refers to the following forms.

Concept

Do you see the L's?

Basic Form

Reversible

Yayoi

Yayoi, or Yayoi Period (弥生時代, yayoi jidai) refers to the following base. This form gets its name because the base looks similar to takayukashiki-soko, which were warehouses on stilts that were supported by pillars dug into the ground. Many of them were built during the Yayoi Period in Japan.

Concept

Basic Form

Tail Setup

Can also power depending on what you do.

Meri (Base)

Also known as Meridodai (メリ土台), this base is one half Yayoi and one half DAA Stacking.

Flat Stacking

Flat Stacking (平積み, hiratsumi) refers to the forms below. The purpose of Flat Stacking is to make your overall chain very flat. Flat chains are generally much easier to extend. It also has the added advantage of using only the bottom three rows of the field. This can be extremely useful when you come to build your third floor as you will have an extra visible row to work with. However it should be remembered that, although this form opens up your options later on in the game, it is fairly restrictive early on. It cannot be easily transformed into meaningful harassment, for example, and is very weak against chain rushes as it is not reversible. Building a chain on a flat base also eliminates the possibility of turning it into a power chain.

Basic Form

Sullen GTR Extension

The transition most commonly used on this form is Sullen GTR, simply because it is the most intuitive extension. You could also use New GTR.

Alternate Extensions

It is also possible to use a standard Vertical Transition (as shown below) depending upon the order in which you receive your puyos. Although this base is more vulnerable to harassment, it is also easier to convert into harassment of your own.

Although the primary function of Flat Stacking is to create a flat base to chain on top of, you can also transform it into a tail base.

Submarine

Submarine (サブマリン) refers to the blue group in the following chainsim. If you think about it, the blue "dives" underneath the chain.

Persian Style

Invented by Kuroro, Persian Style (ペルシャ式, perushaa-shiki), also known as simply Persia, refers to the following bases. It's a special tailing form... that's pretty useless in an actual match because there's too many weakpoints; it's too color-specific to make reliably. For that reason, some Japanese players might actually be slightly offended if you make this form against them because it'll seem like you're looking down on them.

Basic Form

Boxed Persian

This is Boxed Persian (箱入りペルシャ, hakoiri perushaa). The chainsim on the left is where the name comes from. The reds look like they're "boxed in".

Persian Dam

A combination of Persia and Dam Stacking (a power chain).

Diving (base)

After your chain reaches the wall, it dives down and comes back the other way. Similar to Submarine.

Basic Form

Applications

Kuma Stacking

Named after Kumachom, this form is similar to Tanaka Special. Incredibly versatile.

Basic Form

Flat Stacking Type

L-Shape Type

Transition

Reversible

Aztec

A type of Same-Color Chain that contains elements of L-Shape.

Kenny Style

Named after a player named Kenny, Kenny Style (カニ挟み, kani basami) is a form that can function as either a tail or a transition.

Raanet Meteor

Named after Raanet and also called RAM or R@M, Raanet Meteor (らねあっとメテオ, raneatto meteo) doubles as both a chain and a Hellfire. It's constructed out of a combination of L-Shapes, New GTR, and more. In the chainsims below, Hellfire with the blues or start a chain on the left.

Universe

A form developed by Tom. The name comes from the "theory of universal chaining", a concept about having an adaptable board that can quickly extend, dig, or harass for any situation.