X's and O's

a cryptic puzzle by Emily Cox and Henry Rathvon

Solution
We’ve diagrammed a game plan for 9-Across (an 11-letter phrase), using X’s and O’s. Clues whose answers cross X’s and O’s in the grid are listed separately, in no special order within their respective groups. Note that the given X’s and O’s are only markers, and can be crossed by any letter of the alphabet. Numbered entries are clued normally. If entry-separating bars were shown, their pattern would be the same with the grid rotated 180 degrees. Letters marked by O’s, when read downward column by column from left to right, will spell out the plan of action. Letters marked by X’s, read similarly, will give the location.

Across

  • 1.
    Cutting-edge equipment for athletics returned (6)
  • 3.
    Mocking remarks scar Sam badly (7)
  • 5.
    Dimly disturbed about a gentlewoman (6)
  • 9.
    SEE INSTRUCTIONS (11)
  • 10.
    Stop wearing gold for so long (5)
  • 13.
    Promote writer of classic songs (6)
  • 14.
    Charm a stubborn sort with grit, ultimately (6)
  • 15.
    Talk about the French lodge (6)
  • 16.
    What a plane lands on following South America takeoffs (7)
  • 17.
    Parisian address for a woman brought home around morning (6)

Down

  • 2.
    Drop wrench (4)
  • 4.
    Article running soon (4)
  • 6.
    Harry’s right behind star in an old western (6)
  • 7.
    Some terminals with oxygen in Peruvian peaks (6)
  • 8.
    Pitch pursuant to Gardner sci-fi film (6)
  • 11.
    Touch big horn when it turns up (4)
  • 12.
    Heard group on a field form a swarm (4)

X's

  • a.
    Skip first couple of minutes in overtime (4)
  • b.
    Blues about trendy philosopher (7)
  • c.
    Embellishes Los Angeles roads (5)
  • d.
    Listened to canine feature story (4)
  • e.
    Rodent eating second dessert (6)
  • f.
    Mannerly “The Thing” set in Arctic extreme (6)
  • g.
    German pistol turned on Yankee star (7)
  • h.
    Soldiers catching deserter on the house (6)
  • i.
    Insect found in lion’s shed (6)
  • j.
    Lifting chopper outside consists of cheap metal (8)
  • k.
    Auto circling through expensive spread (6)
  • l.
    Rudely disregards small traffic signals (7)
  • m.
    Senator’s impounding district attorney’s vehicles (6)
  • n.
    “The Apartment” actor is dud in audition (6)
  • o.
    Sent Mom one type of bulb (6)

O's

  • a.
    Edited log: “Ate frozen treat” (6)
  • b.
    What’s worn by Oscar’s first screen legend (5)
  • c.
    Cowboys’ home completely captured by German article (6)
  • d.
    Nobleman confused Lear (4)
  • e.
    “Camelot” lyricist accepting a student (7)
  • f.
    Clumsy pet in convertible (5)
  • g.
    Film about crossing a border’s lone, meandering route (7)
  • h.
    Hey, “The Odd Couple” neatnik is not so old (7)
  • i.
    Letters from Margaret Hamilton for the Queen of Soul (6)
  • j.
    Role in changing essence of orange blossom (6)
  • k.
    Wilder sticker not put back (8)
  • l.
    Heavy metal star’s role (4)
  • m.
    Seats of power abandoned by nation’s premier in upheaval (6)