As I’m polishing up my rules I am going to give this a shot. A material breach is when a party fails to substantially perform under the contract. The non breaching party may stop performance or sue. If a breach is willful and/or done in bad faith, substantial performance and equitable estoppel is not available. The breaching party must bear the cost of departing from the contract’s terms. Factors to consider: - is the breach so pervasive that it frustrates the contract? - Did the aggrieved party get the benefit of the bargain? - Did D perform the main part of K and was it enough?