(4E) Skill challenges.

[alhoon]

After some programming, I figured the following for the new skill challenges.
As many of you would know, the new challenges require X successes before 3 failures.

If you want a tough Skill challenge (about 55% chance of success):
If successes required = 4, then the average party member should succeed on a d20 roll of 9 or more.
If successes required =6, then the average party member should succeed on a d20 roll of 7 or more.
If successes required =8, then the average party member should succeed on a d20 roll of 6 or more.
If successes required =10, then the average party member should succeed on a d20 roll of 5 or more.
If you want a somewhat easier challenge (2/3 chance of success), then the average party member should succeed on a d20 roll of 1 less than presented above. I.e. for 8 successes required, a d20 roll of 5.

So when making a skill challenge for say 7th lvl characters (+3 from level, +4 from stats, +5 from trained, +2 from items/backgrounds/racial abilities/co-operation) the modifier of the d20 will usually be +14.
Now, that doesn't include characters that will be required to roll untrained, but it also doesn't include characters that have utility powers that help. Also in this example, the characters that aren't good at the roll, are considered to be using their actions to help the main rollers get the +2.

So a skill challenge that would give them XP like 4 7th lvl enemies should be something that they win 2/3 of the time. That is 8 successes required, with DCs of 19.