log in or register to remove this ad


Stalker0's Obsidian Skill Challenge System (NEW VERSION: 1.2!!!)


If your looking for version 1.1, please go here: http://www.enworld.org/forum/4e-fan-creations-house-rules/232340-stalker0s-obsidian-skill-challenge-system-update-version-1-1-now-pdf.html

At long last, I have finished the updates to Obsidian. If your new to Obsidian, welcome. This system is designed as a replacement to the core Skill Challenge system, so if you are interested in taking your skill challenges in a new and exciting direction, take a look at the pdf and check it out for yourself.

If your familiar with the system, welcome back! I have collected a decent amount of player feedback about the system, but please keep it up! The more you tell me, the better I can make the system in the future.

And now to the new version.

I think the important thing to stress is how little has actually changed. The solid, simple core that has made Obsidian a popular alternative to the regular system has not been touched. Instead, I have done some housecleaning, and added a little window dressing. Here are the highlights.

1) Two segment skill challenges. By popular demand, I have created a series of very simple instructions for you to downgrade the normal three segment skill challenge into a two segment one. If you've ever run a skill challenge and wish it was just a little shorter, this is for you.

2) New player options and optional rules. I have added a few new players options and some optional rules to give people new abilities with their skill challenges.

3) DC change. The DC table has been changed very slightly (at 12th and 13th level). This isn't errata as much as is it clarification. So many people thought the original system had an error in it, I decided to tweak the DCs to make them clearer.

4) Combat Skill Challenges. This is the meat of the new version. Previously, my combat skill challenge system was a very thin model with little to it. I have taken steps to give this aspect of the system a full rework. It now shares some of that solid, simple core that the standard system does. With this piece of the puzzle you will now be able to run your skill challenges in any environment, whether its the party against a trapped room, or trying to disable a trap while fending off a raging dragon.


log in or register to remove this ad


I really like the new combat challenges. I like your reasoning behind making it only 2-3 successes. I also like how beating the challenge provides an advantage rather than bonus XP.

The Follow the Leader and Shifting Primary Skills also seem like really interesting, but simple, ways for the DM to tweak the flavor of various challenges.

I'm not too keen on the new player options. I don't see the necessity of Brazen Action, and I think it would make many combat challenges finish quickly. I think giving up both move actions to get two checks in a single round should be enough for most people. I don't know though, maybe this is exactly the sort of option people want. I do like the simplicity of it, and it may encourage teamwork to protect the skill-user.

I don't like Unburdened at all. The armor check penalty is a major balancing factor on many armors, at least for guys like Rangers and Paladins who's best armor has a check penalty. I don't think a healing surge is an adequate price to pay (my group, at least, never seems to run out of them), and the check penalty is only a -1 or -2 so its presence shouldn't make the challenge unbeatable. I would ditch this rule.

-- 77IM


First Post
How much do you tell the players?

How much do you tell the players about the mechanics of a skill challenge? Should the players know about the consequences of a partial success/failure in advance? Should they know the full list of valid skills, or what the primary skill is for a challenge? Or should they just muddle through with the in-game descriptions of the scenario and keep the mechanics in the background?

How much do you tell the players about the mechanics of a skill challenge? Should the players know about the consequences of a partial success/failure in advance? Should they know the full list of valid skills, or what the primary skill is for a challenge? Or should they just muddle through with the in-game descriptions of the scenario and keep the mechanics in the background?
For a regular skill challenge, I will often tell the players the overall goal, the primary skill if there is one, and what type of challenge it is (physical, mental, or social). That should give the players an idea of what skills to use.

Example: Guys, this is a social challenge with diplomacy as the primary skill. Your trying to convince the duke to let you pass through his lands.

The rest I won't say, like the effect of a partial victory. Sometimes I won't even say the exact effect of a total victory.

I thought I would take some time to explain some of the new features of this version and into the rationale for why they are there:

Two Segment Skill Challenges:

The most common complaint I receive with the basic skill challenge is that its structure is too forced, and in some cases too long. The three rounds provide a solid base for most challenges, and can be strung together to provide longer ones. However, there is no ground for a quicker challenge.

I have completed a lot of math analysis to try and come up with a two segment system that gives approximately the same results as the normal system, but that can be quickly and easily adapted to a DMs use. I was very pleased with the results. While the two segment system isn’t quite as sturdy as the normal system, it is very close. Further the tweaks that a DM needs to make are seamless, just an adjustment of success numbers and DCs. While I still recommend the normal 3 round system for most challenges (as in my opinion skill challenges should be reserved for fairly in depth encounters anyway), I think people will get a lot of good use out of the two segment system.

Combat Skill Challenges:

In the previous version, combat challenges were mainly designed as a quickie way for a DM to conduct a skill challenge in combat, but it didn’t have the polish of the normal system. Further, the idea of the no time limit combat challenge was an optional rule.
The more I worked with it and thought about it, the more I found the no time limit challenge the most appealing. For a normal skill challenge, I liked the sense of time and flow the 3 segments provided, but in combat the structure was already present in combat rounds. In addition, I realized that combat already provides all of the consequences of failure embedded within, the threat of character death.

With that in mind, I constructed a timeless challenge that would consume actions as its baseline. The idea is simple, if you perform the skill challenge and succeed; you gain a benefit that will help you with the rest of the combat. If you fail, then you have wasted actions that could have gone towards just beating up the monsters…which for most players is plenty of failure in the first place.
Another aspect I recognized in my playtests was that in combat, players need a fair amount of incentive to perform actions that aren’t directly combat related. After all, no one wants to be wasting their time when monsters are trying to kill you. One of the biggest disincentives to players is time. Most players want their action to have a quick result on combat. Few people are going to want to spend 3 or 4 rounds on something that might evolve no benefit whatsoever. In addition to this, I recognized that players didn’t work as a team as much in a combat challenge. In a regular skill challenge, a player would try a skill even if he wasn’t the best at it, afterall, he can only help. But in a combat challenge, if that player didn’t have the best skills for the job he would simply attack the monsters. And…that’s perfectly fine. I recognized I was designing the challenges around too much team involvement. In a combat challenge, it’s often only a small part of the party that is participating in a challenge, most times one individual. That person will enjoy the skill aspect of the combat, the others the more direct side.

So with these ideas in place, I created the combat challenge system to provide general bonuses to the players for the combat, or to disable some obstacle(like a trap). The number of successes required was normally very small (2 or 3).That meant a player could theoretically finish the challenge in 1 or 2 rounds, which gives them incentive to try. Of course, with the chance of failure, the challenges can often take a round or two more, but ultimately most challenges should be completed in 2 or 3 rounds.
Ultimately the combat challenge is a more much looser framework than the regular system, simply because combats by their nature are chaotic. But it should give the DM enough framework to create interesting additions to their combats, using mechanics that the players are familiar with.

DC Change at 12th, 13th level

When I created Obsidian, my calculations noted that around 11th level, the party’s success rate was a bit lower than I preferred. Further, when I increased the DC at 12th and 13th level, the success rate dropped even lower than I preferred. My solution was to leave the DC static, and let the success rate naturally settle as the players skills increased.
Unfortunately, this was very confusing to a lot of people. I received a number of questions as to whether the DCs were an error. Afterall, they seemed very unintuitive compared to the rest of the system.

Ultimately, I decided to smooth out the progression in the table. My reasoning is this, currently all of my higher level DCs are based on theoretical parties, I don’t have a lot of empirical evidence yet to see how good a party’s skills really are at those levels. With that in mind, I accepted the fact that there is going to be error in my calculations, so those lows around 11th level could easily be a result of those errors. At this point until I have more concrete knowledge of levels, I prefer to keep the system consistent and easy to understand. However, I will be watching these levels closely, and I’m ready to change the DC again if I feel that the balance of the system will ultimately be served better with the original DCs.

I would greatly like the communities help in this section. If you have a party around 11th level, please let me know what kind of skill numbers your party has, and what kind of utility powers they have that bump skills. The more real info I have about group’s and their skills, the more accurate I can make the system for everyone.

Unburdened Player Option

In my group’s playtest of Obsidian, I noted a great resentment over the armor check penalty. Generally, fighter types should have skills as good as anyone else, at least in their areas of expertise. However, because of the armor check, a fighter type’s best skills were often penalized. An eladrin wizard could have +11 arcana check at 1st level, but a dragonborn fighter in plate only had a +7 athletics check. That difference is pretty large when it comes to skill challenges, and didn’t seem fair to the melee guys.
On the other hand, heavy armor is supposed to have a penalty, some cost associated for its benefit, and I didn’t want to remove that completely. So the answer was to use healing surges. A fighter can now spend one of his resources (one he gets a lot of) in order to counteract the penalties to his armor. He can perform better in skill challenges, but still pays a cost. This option has proven very popular in my group, and so I have decided to make it a core part of the system.

Brazen Action Player Option
With my new combat skill challenge, I wanted an option to let players brave danger for extra skill benefit. It basically allows a player to “ignore” the dangers of combat in order to perform his job. It’s a simple option that should be intuitive to players, and I’m interested to see how it performs in playtesting with other groups.


I ran two of these yesterday, back-to-back, and totally improv. The group was returning from the dungeon but were in the vicinity of bandits, so they decided to try looking for the bandits, and I had to come up with something better than "OK, keep making Perception checks until you find them." Party members were level 2-4.

The first challenge was to figure out the location of the bandit camp. It started as a mental challenge, but at the end of segment 2 they flushed a runner, and had to chase him down, making segment 3 a physical challenge. Then, they had a social challenge to interrogate the guy (Intimidate primary). They got a partial success when the dwarven fighter decided to try for an extra intimidation bonus by cutting off the guy's leg. I ruled this an application of Going for Broke -- it didn't work and the guy passed out, but by then they had enough info to count it a partial success (I gave out a piece of info with each success).

I had printouts of the PDF but didn't show it to any of the players. I just explained it as I went, revealing options (Bold Recovery and Primary Skill) as they became needed. Everybody got the core concept right away.

At first people were trying to use whatever their best skills were but eventually they were trying wacky things. I think it clicked when I explicitly told them that the DC was always 19, and that the only real way they could get ahead was to do creative stuff in the hopes of impressing me enough to give +2 bonuses. Giving out the bonuses is something that I need to get better at, but by the end of the challenge I think it was working well. The party wizard is the type of player who is always trying crazy stuff (and usually it doesn't matter, which frustrates him) but for the challenge he kept getting +2 bonuses, so that was good. Also, I think a really great way to simulate "Aid Another" is through those bonuses -- for example, the warlord and the rogue got a "good cop/bad cop" routine going that used their skills well (Diplomacy/Insight and Bluff/Intimidate/Streetwise) and got them +2 bonuses to both actions on certain segments.

Overall I felt it went really well, and solved most of my issues with the RAW system. The only real problem is the dwarf fighter, who has few skills, low mental scores, and tends to roll poorly. He was more engaged during the Obsidian challenge than the RAW challenges, because he knew he couldn't hose the party by generating a failure, but it was still a little frustrating for him. I think that may be 4e's fault, really, for giving the fighter only 3 skill picks.

-- 77IM


Hey Stalker. I know this is off topic, but you don't have an email option in your profile:

Were you the guy that suggested traps using an active stealth roll vs. passive perception?

If so, I was wondering how you reached the trap's active stealth roll bonus.


First Post
Statistical data for DC values?

Hi Stalker0. Would it be possible for you to post the source data you used to derive the DC table?

One thing I'm interested in trying is to adjust the DC table so that every level is distinct; this gives me the ability to set a level 3 challenge that's a bit harder than a level 2 challenge, for example. One way to do that would be to vary the DCs for each of the 3 rounds of a skill challenge; eg: level 2 might be 19/19/19, while level 3 might be 19/19/20. But I wouldn't want to make a change like that without running it through your stats to see how it changed the outcomes.

I did a lot of mathematics a while back when I was working on the subsystems of Obsidian, but for the whole thing I have used lots of computer simulations as it tends to be faster and can account for variances without a lot of complicated math. So I don't have a good "insert DC to produce win rate" formula for you.

However I can tell you that bumping the DC by 1 for the whole encounter tends to drop a party's win rate by 10%. So bumping it by 1 for one segment is about 3.3% or so. The number varies slightly if the player's know when the DC changes, as that might affect their decision making (aka I am more likely to spend an action point to reroll the skill check if I know the DC is low, since I have a better chance of getting it then if I reroll against a high DC).


First Post
That makes sense. Would it be possible to post the inputs/assumptions behind those simulations? By that I mean what skill levels you assume the party will have at each level -- how do you account for ability score bumps and accumulated magic items?

That makes sense. Would it be possible to post the inputs/assumptions behind those simulations? By that I mean what skill levels you assume the party will have at each level -- how do you account for ability score bumps and accumulated magic items?
Much of that is in the pdf itself. I talk about assumptions that go into the DCs, and ways you can tweak the DCs to fit your party.


First Post
Hey Stalker0,
Got a question for you. Forgive me for not searching through the older post. But I thought I would go straight for the source. What is the difference versus Obsidian and the Alternate Core Skill Challenge System.

Now I know there will be a difference in the math, but besides the hard crunch what is the difference. Now if there is a huge math difference so be it. But I was wondering if there was a big RP difference. I hope I am making some sense. Thanks for your help and I have downloaded Obsidian to look at for now. Thanks again.

Hey Stalker0,
Got a question for you. Forgive me for not searching through the older post. But I thought I would go straight for the source. What is the difference versus Obsidian and the Alternate Core Skill Challenge System.
A big one in fact.

The alternate system uses the same mechanics as the WOTC skill challenge system. I curbed much of the math imbalances in the system, and added new options. However, many of the problems with the original system are ingrained in the math model they used, there's no getting around that.

Obsidian is a brand new design. It is a simplier system, has fewer options, and is also sturdier than the other system. It can tolerate a DM just throwing a +2 here or there much easier than my other system can.

In the end its really a question of what your group wants. Ultimately my group liked Obsidian better so that's the one I support most since I get to actively playtest it.


First Post
Okay, I get it. Alternative System is based on 4E where as Obsidian is your own creations. Thanks for the info. If I have anything else I will let you know.

Magus Coeruleus

First Post
I know this is far out there and tangential, but has anyone thought of using something along these lines as a replacement system for combat itself? That is, instead of tactical grid-based action-by-action combat a system based on a party's general tactics and the DM adjudicating DCs based on how viable their powers and strategy seem in comparison to those of the enemies? I like D&D combat as its own mini-game, but it often feels like fun:timespent ratio is far far lower than that for skill challenges I've run, and I would like plot to move faster. Just curious since I've enjoyed Obsidian skill challenges.

Lonely Tylenol

First Post
The PDF seems to be broken for me. I'm using Adobe Reader version 8.1.2. Another PDF of your stuff (the skill challenges sheet v1.8) works fine.


First Post
This is great. I used it a couple of sessions ago, along with the skill challenges from the Gladiator article and it got major kudos from the group.

Great job!


First Post
I have no specific requests or comments, but I just wanted to drop in and say thanks for making such a solid, fun system. I play in the RPGA with a character that doesn't have very many trained skills, and I HATE how the standard challenges encourage group members to pass or aid another. In my home game, I love seeing my players all grab their dice and get bold when a skill challenge comes up.


First Post
The file download in the OP is corrupt, or at least my acrobat reports it as such, have tried to download it 3 times and nothing :(

NOW LIVE! 5 Plug-In Settlements for your 5E Game