so how does the points affect the chances?
You have to roll below your skill level. Points increase your skill level, making it easier to roll below that value. Items lower what is rolled, making it possible to have a negative roll.
I might be slightly off, but basically let's say you want to activate Charm and its an extreme challenge. If you have increased your skill to 57, you have a 20% chance to succeed, or below a 12 to succeed. If you increase the skill to 100, instead below a 21 will succeed, almost doubling your chances.
Special items lower
what you roll. In the scenario above with maxed skill, you normally would have to roll between 1 and 20 to succeed. Normally, "below a 21" would mean anything from 1 to 21. Let's say you rolled a 23, so a failure. But if you have a bonus item that lowers your roll by even just 5, you have an 18 and so succeed.
Also, because bonus items lower the final roll (instead of raising the target %), it's possible to even roll less than 0. Let's say your natural roll was 3 and you had the same bonus item that lowers the roll by 5. You've now rolled a -2 for your roll. Since the rule is "below a 21", you still succeed. If -2 is the lowest you can get with bonus items, you've still increased the number of rolls (1, 2, 3, etc.) that succeed. With no items, there are 20 rolls that succeed, but with that bonus item you have 25 rolls that succeed (-5 to 20).
