Equivalent Dice for AGE

 

The test roll for the "Adventure Game Engine" is 3d6. I was experimenting with some math and realized the TN 10,11,12 probability chance lines up perfectly with 1d8 die with TN 3,4,5. Therefore you could realistically switch from 3d6 to 1d8+6 without changes to any system numbers. Yes you lose the opportunity to roll doubles but for this thought experiment we are OK with that.

There are few main advantages for 1d8+6 over 3d6. The first is a single die which is easier to do math with and does not have a curved probability distribution (it's a straight line).

The second is that it maintains a compact rolling range which won't feel as swingy as d20 does. The plus six makes a firm foundation such that the average of the roll is only 50% of the base. Compared to d20 where a modifier of plus 1 is only 9% of the overall roll value. A plus one here is more like a +7 which is 60% of the roll value. So much less of the overall roll value is random.

The third advantage is that the plus six portion could actually be combined as part of character creation where the roll is 1d8 but you start out with an average of 6 per ability score. It is less bad to have negative attributes than to have small positive attributes. To support this change you would need to:

• add five to the starting ability table so the average is 6 (since the average is already about 1)
  
• use the existing point buy system, but then add five to all abilities
• add five to any ability score requirement in a talent
  

This third option does require a bunch of number changes, but they are pretty simple additions. It also remove the arbitrary plus 6 and instead hides it as the ability score.

Back to stunts. Stunts are essentially a more generic bonus that a tradition critical strike for more damage. Overall all successful and failure rolls, the average stunt bonus is about 1 stunt point. For successful rolls the average stunt bonus is about 4 stunt points. On a success, double happened about 22% of the time. Therefore I would recommend an equivalent stunt mechanic for would be to crit or award 4 stunt points on rolling a seven or eight (25% chance).

If I was to take more drastic changes I would lower the plus portion to probably about 4 instead of 6. This puts the proportion of random value to ability score at about 50/50 so that the randomness doesn't feel overwhelming at low levels. It also reduces the math to slightly lower numbers on average. I really like how the plus 4 would also remove negative ability scores to where you can state a zero means no ability. You could also switch the die to a 1d6, maybe reduce the plus to 3, to further reduce the numbers.

My main learning from this experiment is that one might better control the feeling of swingy and randomness in your rolls by designing your starting ability scores (on average) to be equal-ish to the average value of your dice such that the portion of randomness doesn't exceed the portion of ability scores. As the character progression improves the portion of randomness is reduced and gives more control to the player.