DecodiVerse uses a structured scope and sequence aligned to UFLI Foundations (University of Florida Literacy Institute), with 30+ levels spanning Kindergarten through Grade 3. Each level defines the cumulative set of phonics patterns a child has been taught — starting with simple CVC words and progressing through consonant digraphs, blends, VCe patterns, vowel teams, r-controlled vowels, and multisyllabic patterns.
When a story is generated, every content word is checked against the cumulative phonics patterns for the selected level. Words that use patterns the child hasn't been taught yet are replaced. Approved high-frequency sight words are handled separately — they're allowed even if they don't follow patterns taught at that level, because they appear in explicit instruction at every grade band.
The grade-band selector (K-early through 3-late) maps directly to specific constraint levels in the scope and sequence. This means a parent selecting “Kindergarten — Just Starting” gets text constrained to CVC words with short vowels, while “2nd Grade — Growing Strong” allows vowel teams, r-controlled vowels, and common multisyllabic words.
Age-appropriate themes are maintained independently of reading level. A kindergartener asking for a story about dinosaurs gets dinosaur content with CVC-level vocabulary — the theme doesn't dictate the words.