CITADEL
TELEPHON
TELEPHONY

CELL
PHONE
TELE

Incidentally, in case anyone wondered why I chose CITADEL as the word, WillLem's previous round made me think of the rule "AKHTBN if it's a Repton 3 level password", but I wouldn't expect anyone here to be familiar with those. so I chose just one 

That's correct    Sorry for the troll round; once I had the idea I wanted to go with it to see how things would play out.

Did you feel sure it was right at this point or was this just probing for a more helpful koan?

White koans:
CITADEL

Black koans:
ADEL       CITADELCITADEL    LEDATIC
C          CITADELL          MNEMONIC
CASDLE     CL                REST
CASTLE     CTAEL
CATLE      CYCLE
CENTURY    GENERATION
CCITADEL   GIGANTIC
CIRCLE     GYM
CI         I
CITA       ITADEL

White koans:
CITADEL

Black koans:
ADEL       GENERATION
CASTLE     GIGANTIC
CATLE      GYM
CENTURY    LEDATIC
CIRCLE
CI
CITA
CL
CYCLE
CTAEL

White koans:
CITADEL

Black koans:
ADEL
CASTLE
CATLE
CENTURY
CIRCLE
CYCLE
CTAEL
GENERATION
GIGANTIC
GYM

White koans:
CITADEL

Black koans:
ADEL
CASTLE
CATLE
CTAEL

Anyway, we should do another round...

White koans:
CITADEL

Black koans:
CASTLE

Well, it was easy to notice that all the white koans were English words, especially after your previous round, and FLY stood out from the others; at first I thought it would be a semantic rule, but trying other insects or other movement verbs led nowhere; then I was just looking at it and it clicked    It helped, of course, that "If only they could fly" is one of the more memorable levels and level names from L1.

A koan has the Buddha-nature if it's a word contained in the title of a Lemmings level. (Specifically, Amiga/DOS L1; my last guesses were meant to probe whether ONML and other L1 versions were included or not.)

FLING
MOON
WAYS

You missed FLEA.

COCKROACH
FLEE
SWIM

FLEA
KOAN
ON
TO

Quote from: WillLem on December 02, 2024, 08:55:27 PMOut of interest, what was "the obvious guess" going to be?

"A koan has the Buddha-nature if it does not contain K." Fortunately, your counterexample works equally well to disprove that.

NO
OT
TON