Pre-Intermediate Level or Level 3 of Japanese Language Proficiency Test (JLPT) feature about 2500 to 5000 characters per book. This level adds 300 words to the vocabulary seen in Level 2. Again, grammer is less controlled than Level 2.
Grammar / 文法
potential form, imperative form, ~とき, ~たら・ば・なら, ~そう(appearance), ~よう(conjecture, metaphor), compound verb, etc.