The Negative Dice Pool is for when things are going wrong for the player. However, you are not expected to have a full hand full of negative dice every turn.
The most basic part of the Negative Dice Pool is the Difficulty Dice (page 6). There is no set number of dice a GM has to give in a situation that doesn’t involve another player. But given that the average player is going to have a Positive Dice Pool of 2, then if you want to maintain a level of “Every roll can fail” then two Difficulty Dice would do that.
The key thing to remember if you’re a GM is that difficulty does not have to scale up to make things harder. The point of the Difficulty Dice is that it adds complexity to a task. A failure can turn a successful action into a fail, but one where it’s just the Advantages that kick in. This can make a mundane task a little more exciting.
Or really, in short, the Difficulty Dice are meant to spice up an ordinary action. Not punish it.
Disaster Dice, however, are fully meant to ruin a player’s day. Just like a Knack Die introduces a critical success, so too does a Disaster Dice add in a critical failure. Rolling one of those is meant to be the punishment.
I recommend that the average roll does NOT have a Disaster Dice. The stakes they add on top of Difficulty Die can make an action turn out extremely bad for a player. If that’s the purpose then add them, however, if you don’t want a player to potentially face heavy consequences then leave them off.
I generally think of them as Boss Fight Dice. That doesn’t mean it has to be a person, just something that the players should be afraid of. Being on the Main Stage during the grandfinals could warrant a Disaster Dice. In a case like that, the lights and noise and crowd all add a special level of difficulty, right? That’s where Disaster comes in.
It’s a thematical upgrade of danger rather than based on Stats and such like Knack.
Complication Dice is what happens when life happens. Those little things that you could never plan for, the proverbial monkey wrench into your machine. Your mic being on the fritz is a Complication. A sudden downpour during your turn would be a Complication.
They can also be the consequences of a player’s previous action. GM’s can give out Complication Dice for stuff like previous interactions the player and NPC have had. You can often use complication dice to show things like social conflicts. Things that don’t make a situation more Difficult, or even make it a Disaster. But it does Complicate your life…
Like the rest of the Negative Pool, it’s not meant to be in every situation or roll. Just when the situation calls for it. Another wrinkle to the plan.