Rule out the usual hiding places first. If the piece really is gone, check the set piece by piece
and leave with the element ID LEGO asks for, or a link to buy the part.
220 pieces in 105 part and color combinations, plus 2 minifigures.
The official piece count includes the 9 parts inside the set's minifigures, which this inventory lists separately; the remaining difference of 1 piece is within the tolerance of the catalog data.
Before you call it missing
Builders who report a missing piece often find it in one of these places. Tick each one off as you look.
Weapon SaiPearl TitaniumPart 98139Element 6270137 or 46468701 spare in the box×1
Tan
1 piece
Plate Special 2 x 2 x 2/3 with Two Studs On Side and Two Raised [Solid Anti-stud]TanPart 99206Element 6132769×1
[No Color/Any Color]
1 piece
Sticker Sheet for Set 71750-1[No Color/Any Color]Part 78482Element 6344849×1
Minifigures
2 figures
Lloyd - Scuba (Seabound)Minifigure, checked as a whole figure×1
Maaray GuardMinifigure, checked as a whole figure×1
Tick each piece as you find it, or mark it missing.
When a piece really is missing
Ask LEGO
LEGO takes requests for pieces missing from a new set through its customer service site. The form asks for
the set number and each piece's element ID, the number printed beside the piece in the parts list at the back
of the instructions. This checker lists both.
Mark a piece missing and your list links it to an eBay search for that part, which also covers pieces from
older or second-hand sets.
Keep a record
Copy or download your missing list (the CSV opens in any spreadsheet), or print the whole checklist and tick
pieces off on paper. Your marks stay in this browser, so you can check a big set over several sittings.