Hung drawn and quartered

Authors of Ars Magica products sign a legally binding Non-Disclosure Agreement (NDA) saying they will not discuss contents of the product before it's published, nor details of the development process. According to legend, any author who breaks this contract will be hung, drawn, and quartered: punished severely and perhaps permanently.

Realistically, what this probably means is that said author(s) would be barred from further writing for the line.

Playtesters also sign NDA's and have therefore sworn weighty oaths of silence, on pain of similar gruesome punishment (not being allowed to playtest any more).