That is not what I was calling rigid. Some of what I was reading was coming across as this is the only way to play and if you don't use the rules you are breaking the social contract.
When I use the term, it refers to what the group has agreed to do at the table and what the group expectations are with regard to each other's roles. This covers everything from announcing a missed session, what other activities are expected at the table, how the players will behave towards each other, expectations of how the PCs will behave with each other and how each role (generally DM/player, but I've seen others) is expected to behave.
[MENTION=42582]pemerton[/MENTION] has a similar understanding, I believe. Part of that social contract from Bullgrit's initial post was they were going to play D&D and he acted in a manner self-described as cheating.
If Bullgrit thinks he was cheating, he was probably breaking the implicit social contract (i.e. an expectation of fair play) at the table or at least the contract he insists on as a player as he points out in earlier posts.
My position is it is wrong to do it and hide the fact from the group. It is not wrong to play that way so long as the group has agreed to accept that behaviour.