Key takeaways
- Rule-based: predictable, cheap, limited. LLM: flexible, powerful, needs oversight.
- Hybrid is common: LLM for understanding, rules for critical actions.
- Choose based on use case and how much variability you can handle.
Rule-based bots follow scripts. LLM-powered bots understand intent and generate responses. Both have a place. The right choice depends on your use case and tolerance for variability.
Rule-based
Predictable, fast, cheap. You define every path. Great for simple FAQs, forms, and flows where you need exact control. No surprises—but no flexibility either.
LLM-powered
Handles variation. Understands paraphrasing and context. Can answer questions you didn't explicitly script. But it can hallucinate, and you need to monitor and tune.
Rule-based
Predictable, no surprises
Cheap to build and run
Limited to scripted paths
Struggles with variation
LLM-powered
Handles varied phrasing
Can answer unscripted questions
Risk of hallucination
Needs monitoring and tuning
Hybrid
Many bots use both: LLM for understanding, rules for critical flows (payments, bookings). LLM routes; rules execute. Best of both.
FAQs
When the flow is simple, you need exact control, or you can't afford surprises. Forms, simple FAQs, booking flows.
When users phrase things in many ways, you have a large knowledge base, or you want the bot to handle edge cases.