The way that challenges are done tries to push two important points.

1. Most people perform on their given skill level most of the time. Sometimes we do better or worse, but we are pretty good at judging what we can or can not do.
2. Doing the tests should be easy and interrupt the narrative as little as possible.

Non-opposed tests

Non-Opposed tests are tests that are set against a particular difficulty. The difficulty is describes with some nifty adjective and sits somewhere on the Competency Ladder. So does the skill that you will use to overcome the challenge. To overcome the challenge you must perform on the required level as dictated by the difficulty. If flying a helicopter through heavy rain and strong wind is a hard thing to do, you must fly like a great pilot.

Now for the dice rolling. Take one D6 and roll it. 2-5 and you perform on your normal skill level. If you roll a 6 you raise your skill level by one rung and you get to roll the D6 again. Another 6 will raise yourself up one more level and so on. A re-rolled 6 will not treat a 1 any different from a 2-5.

If you roll a 1 you perform below your given level by the same rules as for a 6, just the inverse.

Rolling for a probability

Many actions have a probability of succeeding. For example shooting a target. An Average Gunslinger will make an Average Shot less often than a Great Gunslinger, but you can't say that a Great Gunslinger will always hit, just more often. I am thinking it will be structured something like this:

• Each rung has some set die or dice to roll.
• Each difficulty rung has some target number to roll over or under.
• The probability relationship between each rung and difficulty target number must make sense 'in plain english'. For example An Average gunslinger trying an Average Shot would succeed 50% of the times, while a Good Gunslinger would succeed 75%. These are the tricky things to get right.
• You first roll the D6 to see if you perform better or worse than normal. Depending on which rung you end up on, you roll the dice associated with that rung and see if you succeed or not.

Focusing

If you take turns (yes, there are turns for example in combat) you can take your time to focus on your given task, think it all through and stand a chance to do better than usual. For each turn you spend focusing you can 'level up' on one more face of the D6. So if you spend two turns focusing, on the third turn you would get to level up on a 4,5 or a 6. Re-rolled successes will still only succeed on a 6. To keep track of how much you've focused, place the D6 in front of you with the current 'success number' facing up.

If you've focused for 4 turns, on the fifth turn you would level up on 2-6, and stay on your level on a 1.

Stepping up

If you don't have a time pressure to do a task you can keep focusing for enough turns to automatically allow you to step up a level. This is called stepping up. You simply declare that that is what you are doing and you step up a level.

Getting creative

If a task is beyond what is statistically possible for your character, it is time to get creative. Look around for a tool or attack your problem from another angle so that either you get to use another skill (pick the lock instead of breaking down the door) or make the problem easier (climbing a wall difficult wall might be an average climbing exercise using rope and grappling hook). This is where the players really get to explore their options and show off their lateral thinking and it should be encouraged.

Teamwork

Two heads are better than one and so in The Grimm Window. One person (the one with the highest skill) is the leader. For each additional person who joins in to overcome a challenge (assuming that it is something that can be worked on together) adds one die to the roll. If any die come up as a 6, the level is raised by one and all sixes are re-rolled for a chance to raise the level further.

The inverse is not true for ones. The level of the leader is only ever lowered if all dice come up 1.

Opposed Tests

When two characters have different points of views on how a cat should be skinned or more common, which one of them should go on living, there may be cause for opposed tests. So far I have two ways of rolling these kinds of tests so that you, the Storyteller, can pick and choose which one of them that suits the challenge.

Predictable outcomes

For challenges where an informed outsider could fairly accurately predict the outcome of the challenge we use this system. Each person chooses the Skill or Attribute to use. Each person rolls as usual and whoever performs the best wins. If there is a draw, either the result is a real draw or you roll again and again until someone performs better. The decision should be made keeping the story in mind. Whatever makes the game better goes.

If the two characters use different Skills or Attributes there may be a call for mapping the relative use of the selected Skills or Attributes. For example, two characters run towards the holy grail. First one there achieves immortality. Who gets there first? Well, the appropriate Attribute to use for this would be Speed. But if one of them wants to use their Sprinting skill instead, that should be fine. If the Storyteller thinks that an av Average Sprinter would perform on the same level as someone with Good Speed, the second character would have to perform one level higher than his apponent to draw, and two levels higher to win. This mapping should be a quick decision from the Storyteller made on a best instinct call.

If someone has a (dis)advantage this should be mapped in a similar way. For example, if one of the runners is running uphill towards the Grail and the other is running downhill, then we can say that a runner would need to have a Great speed in order to be able to run uphill with the same speed as someone with an Average Speed running downhill. Hence the uphill runner would need to be an e.g. Average Runner in order to tie with a Bad Runner running downhill for the Grail. Again, make these decisions quickly. Better to do a quick and dirty decision than drag it out with discussions and commitees, thorougly killing the mood.

Varied outcomes

Sometimes it doesn't sound quite right to say that someone who is good almost always beat someoene who is average at something. Two people armwrestling is a predictable outcome as described above, but it doesn't quite capture say pigeon shooting. An alternative way to settle an opposed test is for the two parties to roll a D6 each and add the number of the competency ladder where Average is 0 and Good is +1 etc while Poor is -1. So if Mike is a Good shot and Greg is a Poor shot, Mike will add 1 and Greg subtract 1 from their D6 rolls. The probability that a person will win, draw or loose a contest like this, depending on the number of steps above his opponent he is, is as follows:

Common Tests

As we get some experience with The Grimm Window I am sure we will find that certain tests come up time and time again. For example the 'common' situation of Character A deciding to shoot Character B with a gun. Character B doesn't care much for bullets and tries to take cover. Who rolls what, and what percentages does a character have to win? Good question. Once it has been answered and tested to satisfaction we'll write it down here are a common test, and then we don't have to think about it again, making the game flow quicker.