The One SL is compatible with the Play:1, but they cannot be paired together as a stereo pair or used together as a set of surround speakers in a Sonos home theater setup.

Thanks.

So I can have them playing the same music but in different rooms though right?

Yes.

Cheers, much appreciated.

Just to clarify: you can group any Sonos speakers and combinations of speakers. So, for example, a 5.1 Beam, sub and Play:1 surrounds system in one room can be grouped with a Five in another, and a further paired Ones in a third room, etc. 

Thanks for clarifying….

As long as they’re on the same software version. All speakers in a group need to be S1 or S2, not a combination of the two. 

Understood & thanks.

Just for completeness, note that it is possible to stereo-pair a Play:1 and a One, although unsupported, if you have a little technical knowledge:

https://github.com/avantrec/soco-cli#grouping-and-stereo-pairing