Named difficulty tiers are the spec: each tier defines what its level means in generator settings, with an optional gentle drift from start to end across the batch. One tier + one theme list = one single-level book's run ZIP, ready for Book Builder.
Theme list
No list loaded.
Tiers (word search)
Word pool for this tier
8 kids · 12–14 large print · 15–16 standard · 18+ challenging.
Set this to the tier’s start grid: a word longer than the grid cannot be placed.
Pool size updates when a list is loaded.
Start of book
End of book (with drift)
Numeric settings blend puzzle by puzzle; directions and fill switch at the midpoint.