One thing I find is that the book is rather lacking in examples of tests. The few it has are good, but there are so many permutations that it may be helpful to have a discussion of them. What kinds of tests do you call for? Whether they are simple combat tests or fear tests. It may be helpful to show some social tests too. Personally I find they can be the least used.
These were a couple of examples that I used recently. DanteRotterdam had some good examples too.
- Joe is standing in the street when a group of three zombies round a corner and make for him. He pulls his pistol and starts firing. He's got a pistol, is a crack shot, and is aiming, so we will say he has 4 positive dice and a Dex stat of 3. The zombies are shambling, but are unrelenting and horrifying, so they give 2 negative dice. Total roll on positive dice is 5, 2, 2, 1. Total roll on negative dice is 4, 2. The 5 is over the stat so is eliminated. Two 2s from the positive and negative dice cancel each other out. But he does hit for 5 damage (2 successes + 3 pistol damage). But 1 negative die roll (4) is uncancelled. This could be applied as mental stress being that the zombies are still at range and thus described as Joe beginning to freak out as the get closer to him.
- Next round, Joe (Dex 3) starts running for the door of the mall. Looking back, as he runs, he tries to continue shooting. Not able to aim, Joe is down to three positive dice (1 base, 1 pistol, 1 crack shot). The zombies are still coming (unrelenting) but he is running which will throw off his aim (1 negative die) for a total of 2 negative dice. Rolling he gets a 4 and two 3s on the positive dice and a pair of 4s on the negative dice. The 4s cancel each other out leaving a positive pair of 3s and one negative 4. As to the positive dice, I could run this as a normal hit (5 damage again) or (if using the head shot feature) have him take out a zombie with a head shot. As to the one negative die, it could be described as stumbling over debris while running inflicting a point of physical stress or more mental stress as the other zombies keep coming. Personally I'd go with the former as I think taking out a zombie would reduce the horror of the situation somewhat, but either works.
It may be helpful to people to see when negative dice are used or not used. Whether a test can inflict stress. When and if to use features both positive and negative. Feel free to discuss them. I don't think there is any absolute right or wrong way and it may be helpful to others to see alternate viewpoints.