I think from my post yesterday, I was trying too hard to accomplish something that was, as I rightly assumed, simple from the beginning. In tangential arguments I’ve had over which ability scores humans should receive bonuses to, I’ve brought up the number that all ability scores start from, which is ten.

There are long, elaborate arguments about where ability scores start and stuff, but the thing to keep in mind that as the ability scores have been created, modified, and used in conjunction with the d20 System, the ten (and by similar argument, the eleven) is the basic value at which all ability scores begin.

The ten is zero. If a creature or character has a nine or less in an ability score, they receive penalties to their rolls, and if they have twelve or more, they receive bonuses. Ten (and eleven) is where ability scores begin. I realized that’s where investigator skills should start when converting adventurers into Arkham Horror.

First, you have a basic array where all of your skills go from zero to three. Your character’s race immediately bumps up the two abilities (whether they’re both set, or you get to choose one or more of them) to a range of one to four, as appropriate. Finally, your character’s class bumps up its primary skills by one as well.

You can see from the above (assuming the picture loaded correctly) classic Fourth Edition race and class combinations, the racial ability score modifiers and the primary abilities for each class increase the character’s potential ability scores, without setting definite scores. There’s no rolling involved in this, race and class define ranges.

When making checks, you roll a twenty-sided die and add the appropriate modifier, based on however you’ve set your ability scores for the current period (defined by when you last made camp). The next question to answer, for Dungeons & Dragons players, anyway, is probably ability growth. It should be easily answered, though…

At levels four, eight, fourteen, eighteen, twenty-four, and twenty-eight, the player chooses one ability score to bump up by one. This is mostly to reflect the fact that when the player rolls for their ability scores, they often wind up with odd numbers that only need a minor increase, and that Fourth Edition allows players to increase two ability scores at levels ending in four and eight.

Finally, when a character reaches twenty-first level, they should bump up all of their abilities by one, taking into account the fact that paragon and epic tier advancement increases all ability scores by one each. Here they are again twenty levels later:

These characters didn’t do anything especially profound with their ability score increases. They bumped up the abilities they were already using, as one might expect. I’m sure if you implement abilities like this into your game, your players will find a way to surprise you. I haven’t tested this, I’m only working with the powers of my mind.