Previously the calculation for an ability score was done by rolling 1d10 and ignoring the 1s and 10s, which meant that you had a chance of 1/8 of rolling 2, the lowest score. In a game like Cairn the chance of rolling 3, the lowest score, is roughly 1/200. The probability of rolling a given sum in Cairn or a traidtional D20 system follows a dice curve, where the middle values are much more likely than the lowest (or highest) values. With my old rules the distribution is flat, meaning you have the same chance of rolling a middle value as you have of rolling a score that will have you failing your checks 90% of the time. I don't like this.

After making actual considerations of the probabilities I changed the system of character creation to have you roll 2d10 (ignoring double 1s and double 10s) and get the average of the two values as your score, rounding up the division. This makes it so the chance of getting a 2 is of roughly 6%, while the middle value of 6 is a healthy 20% (roughly). Not as good as 3d6 (or 3d10 for that matter) but much better probability than before. I like this a lot more.

Also I increased the threshold for being a wizard to a STR/DEX score of 3 or less, which you have a probability of roughly 15% of getting. Before it was 12.5%.

In conclusion, it was foolish of me to design the original mechanic without giving it proper thought and study. I am new to this and learning as I go. I hope you will forgive this blunder.