King Arthur Pendragon! (does anyone ever call the game that?) has a deceptively complex system for dice rolls.
You have a score that ranges from 1-40 – most commonly in the range 10-20.
You roll d20 and try to get under your score, and a roll equal to your score is a critical success.
So far it’s pretty easy. The tricky part is when your score is over 20.
In that case, roll d20 and add the amount of ability over 20. So if your score is 23, roll d20 and add 3.
Any roll of 20 or higher is treated as 20 and is a critical success.
Also when your score is below 20, you fumble on any roll of 20, but when your score is 20 or higher, you never fumble and that 20 is now a critical success. So your worst result is now your best result.
For some players, switching between rolling under and rolling as high as possible is very hard to deal with – especially when your score changes a lot. For one roll it might be 21, then next 16, and the roll after that 26. And then you roll a completely different ability that has a score of 18, which is at +10 because you’re inspired.
Here is another way to make rolls that has exactly the same probability, but is much easier to work with.
The Alternative System
Roll d20 and add your Score. If you get above 20, it’s a success, and any roll of 40 or above is treated as 40 and is a critical success.
Any natural roll of 1 is a fumble. Optionally: if your skill is 20 or higher, you don’t fumble any more (just like in normal Pendragon).
This has exactly the same probabilities as the standard system but is very easy to use.
Any modifiers to your score are identical to modifiers to the roll – in the standard system, you might sometimes modify the score and sometimes modify the roll, and sometimes both. Think of what happens when you have a skill of 23 and suffer a -5 modifier.
There are two complications.
- Sometimes you are assigned Glory based on your roll.
- When using a Flail or Warflail, a successful roll of 1 means you hit yourself.
In the new system, for complete fidelity, use the following rules:
- Assign Glory based on result -20.
- When using a flail or warflail, you hit yourself on a result of 21 (the lowest possible success).
Those complications are pretty minor. In my experience, players who have trouble with the default system, have a lot of trouble with that system, and none at all with the alternative suggested here.
I have used it extensively, and have never seen any drawbacks to it, but have seen it make a massive difference to some players. That’s enough reason to use it, IMO. What do you think?