|View static image|
|Number of cells||2|
|Year of discovery||Unknown|
The duoplet is a two-cell pattern, one of two 2-cell polyplets (the other one being the domino). It is occasionally seen as a spark, and is periodically produced by certain oscillators such as 41P7.2 (incapable of reflecting gliders) and 34P14 shuttle (capable of reflecting gliders).
It can reflect a glider by 90 degrees, as shown in the infobox.
In other rules
It is a period 2 oscillator and also a phoenix in many Life-like cellular automata, namely all rules with B2 and without B0, B1 or S1 such as Seeds. More specifically, it requires the isotropic non-totalistic transition B2e without S1c, as shown on the left.
In rules without B0, B1 or B2 (B2e), and with S1 (S1c), it is a still life.