A fantastic supplement. Quite simply, this is something every DM should get their hands on--certainly if planning to run Descent into Avernus, but really for any campaign in which devils will make an appearance. The whole conecept of devil contracts--while incredibly exciting--can seem daunting to a DM from a mechanical perspective; how exactly should I work them into a game without bogging things down or letting details slip through the cracks? The Devil's Advocate guide eliminates these concerns and provides a richly detailed yet simple framework that should make for some highly memorable in-game moments!