d5 - a d5 is a roll of d6 where 6 is read as ZERO.
5x5 roll - A 5x5 roll is two d5 rolls multiplied together.
Ability Scores range from 1 to 4.
Skill Ranks range from 1 to 4 plus UNSKILLED.
Ability Score multiplied by Skill Rank equals target to roll or less on a 5x5 roll.
A roll of ZERO always succeeds.
A roll of TWENTY FIVE always fails.
Skill Ranks can have a +1 or -1 applied as a positive or negative rank shift respectively producing the following range of possible target numbers.
Ability of 1 | Ability of 2 | Ability of 3 | Ability of 4 | |
Weak | -1 | 0 | 1 | 2 |
Unskilled | 0 | 1 | 2 | 3 |
Skill of 1 | 1 | 2 | 3 | 4 |
Skill of 2 | 2 | 4 | 6 | 8 |
Skill of 3 | 3 | 6 | 9 | 12 |
Skill of 4 | 4 | 8 | 12 | 16 |
Skill of 5 | 5 | 10 | 15 | 20 |
Weak - This result only occurs when a player attempts to do something as unskilled and the GM has applied a negative rank shift. When attempting a "weak" task roll, the target number is base ability score -2.
Unskilled - If you have no skill for the task you are attempting you must attempt the task as unskilled. When attempting a task roll as "unskilled," the target number is base ability score -1.
Skill of 5 - A skill rank of 5 is only possible when a player attempts to do something with a skill rank of 4 and the GM has applied a positive rank shift.
The 5x5 roll
-1* | 1 in 6 | 17% |
0 | 11 in 36 | 31% |
1 | 12 in 36 | 33% |
2 | 14 in 36 | 39% |
3 | 16 in 36 | 44% |
4 | 19 in 36 | 53% |
5 | 21 in 36 | 58% |
6 | 23 in 36 | 64% |
8 | 25 in 36 | 69% |
9 | 26 in 36 | 72% |
10 | 28 in 36 | 78% |
12 | 30 in 36 | 83% |
15 | 32 in 36 | 89% |
16 | 33 in 36 | 92% |
20 | 35 in 36 | 97% |
*How do I roll a -1?
It is possible (though rare!) that a character with an Ability Score of 1 (reduced through combat) attempts a task unskilled for which the GM applies a negative rank shift. This would require the character to roll a -1 to succeed at the task. There is a special rule for this. Read the -1 as "roll -1 dice." That is, you must attempt your task roll with only 1d5. Since a roll of ZERO always succeeds, if you roll 0 the task was successful.
There you have a quick over view of how the dice are used in combination with Ability Score and Skill Rank to resolve tasks.
Regards,
Jeff Moore.