What Spellbook does well.
Spellbook is a Microsoft Word add-in that augments contract drafting with AI: clause suggestions, redline review, contract benchmarking, draft generation. The team is product-focused and the off-the-shelf experience for a corporate or transactional practice is genuinely good. Solo practitioners and small firms get meaningful leverage out of it on day one.
Where Spellbook is the right answer.
Three patterns:
The transactional or corporate practice that wants AI in Word, not in a separate tool. Spellbook's strength is the seamless Word integration. Attorneys keep their muscle memory; the AI shows up where they're already drafting.
The firm whose contract patterns are mostly standard. Spellbook is trained on a broad corpus of contracts. Firms whose work fits common patterns (NDAs, service agreements, SaaS contracts, employment) get most of the value the off-the-shelf product provides.
The firm that doesn't have a deep clause library. Spellbook brings its own benchmarks. Firms without strong internal precedent libraries benefit from that breadth.
Where custom AI is the right answer.
Three patterns:
The firm with a deep, differentiated clause library. If your firm's competitive edge is your forty years of M&A precedents, your specific deal terms, your specific opposing-counsel patterns: Spellbook's generic training dilutes that edge. Custom AI on top of iManage or NetDocuments trains on your archive specifically.
The firm whose AI need extends beyond drafting. Spellbook is great for drafting and review. The leakage at most mid-market firms is in time capture, intake, matter summarization, and knowledge retrieval, workflows Spellbook doesn't address. The 47-attorney firm with $1.4M in unbilled-time leakage cannot solve that with Spellbook.
The firm with strict data-residency requirements. Spellbook ships data through their cloud. Custom AI runs in the firm's own Azure or AWS tenant under NDA, with permissions and ethical walls preserved.
What we recommend.
If your firm is a transactional / corporate practice with mostly standard contract patterns, try Spellbook for 60 days at the per-seat tier. It is plausibly all you need.
If your firm is litigation-heavy, has deep precedent value to preserve, has data-residency constraints, or has leakage workflows beyond drafting, run the Billable-Hour Recovery Diagnostic. The number on screen will tell you whether the leverage is in drafting (Spellbook fits) or somewhere else (custom commission fits).