To continue on with my tweaks to skill challenges, I’ll add a few more points on aiding others and detail the effects of critical failures and successes.
Each skill challenge I write up has a set of primary skills and secondary skills. I try to list off skills that would provide a direct solution to a challenge as the primary skills. Skills that might have an application I consider secondary skills. If players use skills from either of these sets, they gain a +1 bonus to their checks. The main difference between primary and secondary skills is that players can only assist characters making checks with primary skills.
I further tweak cooperation checks also. If players fail their roll to assist another character, they actually give the target character a -2 penalty to the current check. So players assisting another can either hinder, or help, their party members. This keeps them involved and helping towards the group passing the challenge if they don’t want to risk earning failures, but adds a small element of risk to it.
Keep in mind with everyone assisting 1-2 players, you will likely get a partial success before a complete success. Yes, this makes it easier for players to pass the challenge but typically they just barely fulfill the conditions for doing so (and get half the XP).
I use elements of critical failures and successes for rolls of a natural 1 and 20. A natural 1 automatically grants a -4 penalty to the current check, and for the next roll on the following turn. So if the current total including all modifiers (including the -4 penalty) beats the target DC, a natural 1 one can still be a success. On a natural 20, the check is automatically a success and the following turn the player can add a +4 bonus to their roll.
A quick summary for how I run my skill challenges:
• Each challenge has 3 possible results: complete success, partial success, or failure. A partial success is typically 2 less the passed checks needed for a complete success. For a trivial challenge, a partial success is 1 less (4 for a complete success, 3 for a partial success, all before getting 2 failures). A partial success is worth ½ the XP a complete success would grant.
• Challenges have 1-2 skills assigned as either primary or secondary skills. If players use these skills, they gain a +1 bonus to their check. Only players making checks with the primary skills can be assisted by other players.
• If players successfully assist a player, they grant a +2 bonus to the current check. If they fail, they grant a -2 penalty to the current check.
• A natural 1 incurs a -4 penalty to the current check, and to any rolls made the next turn. A roll of 1 may still result in a success.
• A natural 20 is an automatic success and gives a +4 bonus to a roll for the following turn.
• All the players describe their actions. The DM and players determine the likely skill used. Players then all make rolls and check their results against the target DC (modifiers from players assisting other characters are also applied). Results are tallied and then used to determine if the challenge is passed. This is repeated until a complete success, partial success, or failure is reached. Remember that all players are contributing every turn (either by assisting or making skill check attempts).
I like having layers of results for skill challenges. A key point to this is making sure that partial successes mean the players ‘just squeeze by’ claiming a victory. Typically I’d be willing not only to give an advantage for earning a complete success, but also be willing to incur some penalty for obtaining a partial success. Earning action points and taking away (or granting) healing surges work great for discriminating between a complete and partial success.