general rule of thumb is you have to roll under the characteristic of the skill you are using on 2d10's one being the 10's and the other the units or a d100 if its easier. But you get a bonus or a negative for what degree of difficulty it is.<br/>ie. reading a low gothic flyer would most likely require a easy (+30) Literacy (int) test.<br/>so just roll under what your intelligence is, plus (or minus) the difficulty.