This chapter provides evidence for the productivity of Chinese character grammar from corpora. Quantitative modeling demonstrates that characters have been generated through regular processes of varying degrees of productivity. Analyses of the ancient small seal script show that its character morphology was already similar to that of modern regular script, though less grammaticalized, with semantic radicals still lacking allomorphy and reduplication having fewer restrictions. By contrast, small seal script had a completely different character phonology, not only with a totally different stroke inventory but also no clear prosodic template. Modern simplified characters are illuminating in another way, since the system generalizes traditional character grammar even while replacing characters and constituents. In simplified character morphology, more semantic radicals appear at the default left edge and show position-dependent idiosyncratic allomorphy, and by simplifying constituents, reduplication sometimes reflects template structure more overtly. Simplified character phonology also maintains constraints on stroke combinations and stroke size (prominence), though curving and hooking have become less productive. Character patterns also vary in productivity across typefaces and handwriting styles, with dots particularly inconsistent. Individual writing habits and slips of the pen are also revealing, especially about character morphology, as are characters invented for playful or artistic purposes.