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.
Large Figure Weapon Accessory, Flame / Lightning Bolt with Axle Hole with Marbled Trans-Yellow PatternTrans-RedPart 11302pat0001Element 6016236×1
Plates Round Curved and Dishes
1 piece
Dish 9 x 9 Inverted with Pin Hole (Radar) and Gold Phoenix and Flames PrintPearl GoldPart 98606pr0002Element 6077637×1
Projectiles / Launchers
1 piece
Projectile, Large Figure Weapon, Zamor Sphere / Ball with Marbled Yellow PatternTrans-OrangePart 54821pat0006Element 6075599×1
Technic Beams Special
1 piece
Technic Beam 1 x 3 with Ball Joint in MiddleDark Bluish GrayPart 98577Element 6001085×1
Tiles Round and Curved
1 piece
Tile Round 1 x 1Trans-OrangePart 98138Element 6514197 or 6274747×1
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.