You all remember this one. Using 4 letter words, change one word into another, changing one letter at a time. Disputes on words will be settled using Merriam-Webster’s online dictionary. Simulposts will be decided by the shortest list of words. If it’s a tie, the first poster wins, and their challenge is used.
I’ll start with SILK to FROG.
bilk
bill
boll
bolt
boat
blat
flat
flag
flog
frog
Challenge:
GRAY to BLUE
GRAY
TRAY
TREY
TREE
FREE
FLEE
FLUE
BLUE
LION to LAMB
LION
LIMN
LIMB
LAMB
Try :
DOOR to FISH (I don’t know that there’s a guaranteed solution there, is that okay?)
Ok, I checked my words at m-w.com to make sure, and when it said that it was “one of more than 1,000,000 entries available at Merriam-WebsterUnabridged.com”, I took that to mean that the word exists, but I didn’t want to register to see the definition. If need be, I can access the O.E.D. online through the university to check definitions.
Door
Dool
Fool
Foul
Foud
Ford
Fork
Firk
Fisk
Fish
Next: Play to Game (I have no idea if this one is possible).
Hm. Worked it myself… which word did you think was dodgy? I can do it without Dool or Foud.
Difficult, but not impossible.
Play -> Ploy - > Plow - >Blow->Blot->Boot->Bolt->Dolt->Dole->Dome->Dame->Game.
There’s probably a better way.
Next: SEND - > GLOW
I think it’s more fun if we don’t know if they’re possible! 
SEND - > GLOW
sent
seat
beat
boat
boot
soot
slot
slow
glow
DUDE - > LASS
Dude
Duds
Dads
Lads
Lass
Mule --> Idol
Dude -> Duds -> Dads -> Lads -> Lass
SHIP -> BOAT
Nah, let me retract that one – I don’t think there’s any way to get to IDOL
MULE --> HORN
Yeah, I was wracking my brain on IDOL.
Mule -> Mole -> More -> Morn -> Horn
SHIP ->BOAT.
Ship
Shop
Shot
Slot
Slat
Seat
Beat
Boat
BOOK -> READ
Book -> Boot -> Boat -> Beat -> Bead -> Read
KING -> JACK
Book
Boot
Boat
Beat
Bead
Read
Walk --> Ride
King
Sing
Sine
Sane
Sank
Sack
Jack
Walk --> Ride
Walk -> Wale -> Wade -> Wide -> Ride
SKIP -> JUMP
What, did I find an impossible one? Hmm…
No, I can do it with six intermediary words. I’ll give everyone a while longer.
SKIP
slip
slop
plop
poop
pomp
pump
JUMP
SKID – MARK
SKID
said
maid
mail
marl
MARK
feel --> good
Feel, feed, weed, weld, geld, gold, good
DUMB – LUCK