'rule-based' originates from the combination of 'rule' and 'based', where 'rule' means 'a prescribed guide for conduct or action' and 'based' means 'having as a foundation'.

'rule' comes from Old English 'rēol', and 'based' comes from Middle English 'basen', both eventually forming the modern term 'rule-based'.

Initially, it meant 'founded on rules', and this meaning has largely remained the same in modern usage.