RUCKSACKS is a playable word

rucksack Scrabble® Dictionary

noun
pl. rucksacks
a knapsack
71 Playable Words can be made from "RUCKSACKS"
   2-Letter Words (4 found)
   3-Letter Words (17 found)
   6-Letter Words (3 found)
   8-Letter Words (1 found)
   9-Letter Words (1 found)