Yes, though the ISDA docs have standardized most of it. But there are also a couple of major types of contract. (a) if there's a Credit Event, the protection

Yes, though the ISDA docs have standardized most of it. But there are also a couple of major types of contract. (a) if there's a Credit Event, the protection seller pays 100 for the distressed debt (essentially taking a loss equal to however much the value of the debt fell). (b) if there's a Credit Event, the protection seller pays EUR40 (fixed payout, with a specific 60% recovery assumption). By playing on the mix of these CDS, people are probably already be playing on the post default value of Greek Debt, even before anything has formally happened. My guess is that process started over a year ago.