From the General Rules Chapter:
Storychips is a storytelling RPG. That means that the most important thing is to tell to the other players what happens in the story. Every protagonist (i.e. player) has his personal character and tells to the others what his character does. The storyteller (i.e. the game master) will describe everything else: Places, non-player characters, events and so on. During the story at some point the question will arise if a character is able to do what he plans to do. Is the fighter able to defeat the fearsome orc? Is the rogue good enough to pick the lock? Does one of the players know the legend of the black dragon king good enough to deduce where its lair is? To answer these questions we use the storychips.
Storychips and difficulty of tasks
Every character has a certain number of storychips with different values (compare chapter 3 Character generation). When the situation arises that it is not obvious if a character is able achieve his goal the storyteller secretly determines how difficult the task is. In storychips there are 5 degrees of difficulty: banal, easy, medium, hard and heroic. When the storyteller has decided upon the difficulty the protagonist decides which of his storychips he wants to play. If the storychip has at least the same value as the the difficulty of the task the action is a success and the protagonist and the storyteller go on with describing the positive outcome of the action. Otherwise they describe the negative outcome.
To make thing a little more interesting there are two more rules about the storychips. The storychips do not only have a value but they also have a denomination. There are five denominations: body, fighting, healing, roguery, lore and magic. If you play a chip the denomination of the storychip must fit the task ahead.
The last rule you have to know is that you can play more than one storychip at once. E.g. if you think the task ahead has a medium difficulty but you don not have a medium storychip in the right denomination you can also play three easy storychips from the that denomination because three easy storychips (value 1) add up to a total value of three which is exactly the value required for a medium task. The only exception to the rule is a heroic task. Heroic tasks have a value of 9999 which mean that you cannot do a heroic deed if you do not have a heroic storychip.