Does Reasonable Endeavours Mean Anything?

A favorite legal drafting trick is to play around with the strictness of obligations. Rather than say Fred must deliver the rocks to Barney within 7 days, why not say that Fred will use reasonable endeavours to deliver the rocks to Barney within 7 days. If the contract says "must" then Fred's failure to deliver will be a clear breach. If it says "reasonable endeavours" then Fred may well get away with delivering late, or not at all.

In light of a recent English decision (see Rhodia v Huntsman for more info) on the meaning of "reasonable endeavours", we now present a menu of phrases for your drafting pleasure:

1. "Must" is strict. It's an absolute or strict obligation. You must do it.
2. "Shall" is strict too. See "Must".
3. "Best endeavours" is not strict, but you do need to act in good faith, and you do need to do all that a reasonable person reasonably could do in the circumstances.
4. "All reasonable endeavours" falls somewhere between "Best endeavours" and "Reasonable endeavours".
5. "Reasonable endeavours" is "less stringent" than best endeavours. It may even be "appreciably less" stringent. It doesn't require much more than an "honest try". But it does require more than a dishonest try. You do need to try, a bit.
6. "Efforts" is the same as "Endeavours". You say "reasonable endeavours", I say "reasonable efforts". You say "tomato", I say "tomato"...
   

There's a good summary (albeit slightly dated) here.