We have to find eight 1-acrosses in the solutions, not otherwise defined.  Not knowing which solutions were undefined made this a little trickier than usual but fortunately I had at least heard of all the 1-acrosses.  Thanks Chalmie.
There are 8 undefined PLAYWRIGHTS in the solutions.

| Across | ||
| 1 | PLAYWRIGHT | Writer wary about being in difficulty (10) | 
| anagram (about) of WARY in PLIGHT (difficulty) | ||
| 6 | OFFS | Kills rotten saint (4) | 
| OFF (rotten) and S (saint) | ||
| 10 | SWEDE | European formed union in the home counties (5) | 
| WED (formed union) in SE (the Home Counties) | ||
| 11 | SLAPHEADS | Unexpected help as bills come for bald men (9) | 
| anagram (unexpected) of HELP AS then ADS (advertisements, bills) | ||
| 12 | STOPPARD | Do better than average in southern Germany (8) | 
| TOP (do better than) PAR (average) in S (southern) D (Deutschland, Germany) – a PLAYWRIGHT | ||
| 13 | RINSE | Climb over pole to wash (5) | 
| RISE (climb) containing (over) N (north, a pole) | ||
| 15 | TERENCE | Recent disturbances have a point (7) | 
| anagram (disturbances) of RECENT with E (a point, of the compass) – a PLAYWRIGHT | ||
| 17 | RADIANS | Gunners returning talked about new angular measurements (7) | 
| RA (Royal Artillery, gunners) then SAID (talked) containing N (new). I can’t see “said” and “talked” as synonyms: say takes an object (what you say) but talk does not. | ||
| 19 | INSPECT | Look over current book containing design (7) | 
| I (current, electrical symbol) NT (New Testament, a book) containing SPEC (design) | ||
| 21 | IONESCO | Tortellini one’s cousin swallows (7) | 
| found inside (swallowed by) tortellinI ONE’S COUsin – a PLAYWRIGHT | ||
| 22 | DORIC | Sort of column found in Gondor, I confirm (5) | 
| found inside gonDOR I Confirm | ||
| 24 | UNSOUGHT | Classy shotgun goes off, though it wasn’t ordered (8) | 
| U (classy) then anagram (goes off) of SHOTGUN | ||
| 27 | EURIPIDES | Brussels detective travels around (9) | 
| EU (European Union, aka “Brussels”) then PI (private investigator, detective) inside (with…around) RIDES (travels) – a PLAYWRIGHT | ||
| 28 | BELIE | Misrepresent ideology, ignoring final part (5) | 
| BELIEf (ideology) missing last letter (final part) | ||
| 29 | GILL | Breathing apparatus is good – and bad (4) | 
| G (good) and ILL (bad) | ||
| 30 | TRESPASSES | Illegally enters health resort protected by locks (10) | 
| SPA (health resort) inside TRESSES (locks, hair) | ||
| Down | ||
| 1, 26 | PASS KEYS | Apes Sky’s devious means of getting in (8) | 
| anagram (devious) of APES SKY’S | ||
| 2 | APERTURES | Openings like to be filled with fresh flower (9) | 
| AS (like) contains (to be filled with) PERT (fresh) URE (the River Ure, something that flows) | ||
| 3 | WHELP | Give birth with assistance (5) | 
| W (with) HELP (assistance) | ||
| 4 | INSTATE | Establish where some people lie about being late (7) | 
| dead people (who are late) lie IN STATE | ||
| 5 | HOARDER | Ring more difficult to keep for collector (7) | 
| O (a ring) inside (with…to keep) HARDER (more difficult) | ||
| 7 | FRAYN | Fighting over the last bit of bacon (5) | 
| FRAY (fighting) then bacoN (last bit of) – a PLAYWRIGHT | ||
| 8 | SUSPENSION | Enforced break in South American hotel (10) | 
| S (south) US (American) PENSION (hotel) | ||
| 9 | SHERIDAN | Woman’s passport maybe found in hospital (8) | 
| SHE (woman) ID (passport) inside SAN (sanatorium, hospital) – a PLAYWRIGHT | ||
| 14 | STRINDBERG | Series about city space being demolished in December (10) | 
| STRING (series) contains (about) DecemBER missing (with…demolished) EC (The City, from the City of London postal code) and EM (space, printing) – a PLAYWRIGHT | ||
| 16 | NO ESCAPE | Can’t get out votes against head (2,6) | 
| NOES (votes against) and CAPE (head) | ||
| 18 | AESCHYLUS | Clue “shy” as anagram (9) | 
| anagram (anagram!) of CLUE SHY AS – a PLAYWRIGHT | ||
| 20 | THUNDER | Tom Hanks initially sedated by loud noise (7) | 
| initial letters of Tom Hanks then UNDER (sedated) | ||
| 21 | INSISTS | Is definite hot relative is out of the way (7) | 
| IN (fashionable, hot) SIS (sister, relative) contains (is out of, outside of) ST (street, the way) | ||
| 23 | RURAL | Country’s rare flower (5) | 
| R (rare) and URAL (a river, something that flows) | ||
| 25 | UMBRA | Pass British artist in shade (5) | 
| UM (pass, “I don’t know”) then BR (British) RA (Royal Academician, artist) | ||
| 26 | See 1 | |
definitions are underlined
I write these posts to help people get started with cryptic crosswords. If there is something here you do not understand ask a question; there are probably others wondering the same thing.
Not a good theme for me but I managed to finish. Took a while to think of OFFS for 6a which then led to FRAYN, my LOI and a DNK. The blog doesn’t contain a parsing for 25d. I felt that UM for ‘pass’ seemed weak since it suggests hesitancy rather than passing, unless I am misreading the clue.
I seem to have gained a reputation for mentioning typos – this time it is Private Investigator in 27a, not DI.
Re 25d -UM and ‘pass’ could equal “I don’t know” in response to a question.
First one I saw was IONESCO so I was off and running on this little bard-crawl
Thanks PeeDee and Chalmie.
Hovis, please keep on looking out for the typos, I can’t see my own typos at all. In this case I think typo is a rather too polite a way to describe the error: “mistake” would have been more accurate!
I seemed to have completely forgotten about 25dn. All fixed now.
I still think somebody saying “um” or “er” suggests he or she is still thinking about it, rather than saying they do not know. Is this just me?
I agree with you there Hovis, but my take is that is doesn’t really matter. If everything had to be a perfect synonym then the world of crosswords would be a duller place for it.
That said, it is still interesting to point these things out and discuss them. I read Private Eye regularly and their Pedants Corner is one of my favourite parts. Some of the contributors take correction of trivial inaccuracies to a quite sublime level.
I guess we all have our differences in how far we can stretch our ‘synonyms’. Maybe I am being a bit too pedantic, or is it pernickety? Never was quite sure of the difference. Hope they never take ‘um’ that way on Mastermind 🙂
Thanks, PD & commenters.
Er, um.
Thanks to Chalmie and PeeDee. I took a long time before seeing OFFS and that gave me FRAYN, my last PLAYWRIGHT, but I was defeated by SLAPHEADS, a term I had never heard of. Still, a very enjoyable puzzle.
I found the “um” particularly irritating since I had what seemed a perfectly acceptable alternative to “umbra” RAs are assumed to be British, so CO-RA-L seemed to be as good a shade (hue) as any other until it made a mess of the SE corner.
Did not finish this … with all the playwrights flummoxing me. Nevertheless, it was a very enjoyable experience and, as ever, great learning the solutions here. Many thanks.
Thanks PeeDee.
I’d advise Chalmie not to seek employment in a hairdresser’s salon as he doesn’t appear to know the difference between WASH & RINSE. 🙂
Thanks Chalmie and PeeDee
Quite a challenge to get finished that took two sessions to do. STOPPARD (who I did not previously know) was my way in to the theme but quite a way through the puzzle. Also did not know of STRINDBERG nor FRAYN (although I had heard of his play “Noises Off”) but was happy to learn about them.
Like others I struggled to find OFFS for a little while and that eventually led to FRAYN which was my last in as well.
Lots of interesting clueing and a nicely integrated theme in which each of the playwrights could be readily enough deduced from the wordplay.