D&D 5e: Skill Checks, Success, and Statistics

As someone who has run D&D games (of the latest three editions) on and off for the last fifteen years or so, I have gotten into a pretty standard rhythm and take a lot for granted. As I discussed elsewhere, I have finally gotten the chance to play a character in a "normal" campaign (not a one-off, not a total homebrew) and I am very grateful to my new DM for letting me sit on "the other side of the table."

As a result of my new perspective, I've realized that one thing I always took for granted is skill check timing. The pace of a game's skill checks is critical to how certain skills, abilities, and even role-playing strategies are understood, utilized, and effected.

For example, consider how often you (as a DM) or your DM asks for:

• Stealth checks
• Perception checks
• Persuasion checks
• Deception checks

 Let's take Stealth as our exemplar.

• If the check is asked for once per "stealth session," a good roll allows a skilled Rogue to go through an entire castle worth of bad guys undetected.
• If the check is asked for a few times per "stealth session," a good roll allows a skilled Rogue to get in the door--but doesn't quite guarantee success. [As I'll discuss below, theoretically, a bad roll could be mitigated by a second or third check, given the right circumstance.]
• If the check is asked for multiple times per round, a good roll means little--the chance of failure goes up as the number of rolls increases.

This model, I feel, bears out in all of the above skills.

• The key is,  the more rolls a PC has to make in a (certain kind of) skill, the greater the chance for failure in the endeavor.  
• Similarly, and just as important, if only one opportunity for success is offered, the chance for failure feels greater.  
• And lastly, a limited/low number of rolls where a failure can be mitigated by a few successes provides (statistically and, I hope, satisfyingly) the greatest chance of success for PCs. 

My point is, I believe there's a sweet spot between a single skill check and an ever-increasing number of skill checks that ultimately provides the greatest chance at general skill success. (Note: that doesn't mean the DM should always be searching for that sweet spot; it is possible that the chance for success should only be offered in a single check, or that multiple checks should be required. It depends upon the situation.)

For the skeptics, let's try some math to back up my assertions. Using our above example, assume a low-level Rogue has a +4 in Stealth and a +2 proficiency bonus for a total of +6. She wants to sneak into a fort, at night, past two guards who are reasonably alert. There are plenty of places for cover, but it's a fifty-foot trip past the guards and through the doorway at a distance behind them. Seventy-five feet if you want to really take a wide arc.

The DM calls for one stealth check to go the whole way, though it will take about three rounds for the Rogue to traverse the distance (depending on how speedy she is and how slowly she's going). The guards roll (or the DC is) a 15. With a +6, she needs a 9 or better, meaning a 55% success chance. Not great, but not terrible either considering how low a level she is and the difficulty of the DC.

Now, what if the DM calls for a check twice a round for all three rounds? That's a total of six checks, and any one failure among them alerts the guards. The probability of making the check successfully all six times drops to 2.7%! That's unreal. Even if the DM only calls for three checks, assuming one failure fails the batch, the chance for success falls to 30%.

But, what if we add in a safety net?

What if we make it so that a failure can be mitigated by other successes, but keep the three checks? In this case, the math is easier if we look at the odds of two failures happening over three checks and then reverse it. In fact, we can look at our old 30% from our last experiment; it's the same as the failure rate in this one. That means we increase the odds of success from 30% (when you must succeed at all three) to 70% (when you must succeed at only 2 of the 3).

Such a simple change, but it makes a huge difference.

 In other words, a DM can actually increase the success rate of a player's skill checks by adding additional checks provided those additions are offset by a simple one-failure-is-mitigated safety net.

I had stumbled onto this idea intuitively, but only when I saw how another DM was pacing his checks did I realize that I could math my way to a better understanding. Again, I don't endorse using this mechanic all of the time, but the DMs out there can use this information to be mindful of the effects of asking for multiple skill checks. The DCs/opposing-checks are designed (in most cases) to be one-offs, and the more checks you throw the worse the odds are for the PCs. On the other hand, building in the possibility of an "acceptable failure" is a way to increase the odds.

In either case, the key to successfully using this methodology is to generally not let the PCs know what the DC is (when possible) so that you can decide in media res if this particular skill check sequence should have a fail-safe.

Hope this idea is somewhat enlightening! Happy gaming.

D&D 5e: The Hoard of the Dragon Queen

After a lengthy hiatus, I'm back! This time, I'd like to discuss my thoughts on the Hoard of the Dragon Queen adventure path. For the uninitiated, this is the first "module" for the 5e game. Developed as the first half of the Tyrrany of Dragons campaign, Wizards of the Coast partnered with Kobold Press (and two veteran designers) to produce this book and its companion, Rise of Tiamat.

Spoilers Definitely Ahead.

The group I DM for has finally finished all eight episodes after (roughly) a year of playing between once and twice a month. It took us roughly ten "sessions" of play time to go through the book's contents. The sessions ran from small 2 hour evenings (very rare) to marathon 10 hour die-hards (only once), but on average each session was between three and four hours.

We continued the story of the Lost Mine of Phandelver when starting Hoard of the Dragon Queen. That is, my players' PCs were roughly level 4, had already completed the sandbox-y Lost Mine of Phandelver module and were transitioned into this campaign. I used a transition that involved placing a connection between an encounter the PCs had (innocuous enough) in one of the towns in the Phandelver module and the first episode in the new book. The connection provoked a journey that required a few roleplaying encounters and one combat. For my notes on this transition, see my discussion on the EN World forums.

I will say that this method absolutely worked, and I would recommend it to anyone--particularly new DMs. Indeed, I'm willing to recommend the entire Hoard of the Dragon Queen, provided such a DM is willing to look at the many well-done blogs out there that have homebrew errata to "fix" or avoid some of the issues.

Overall thoughts:

• Structure: The jump from sandbox-y to narrative track was a bit jarring, but for my party (who like a mix of both) it seemed to work well. The key for my group was making sure to continually revisit the goals of the party as we started each session: why are you traveling here? Who are you looking for? What is the end-game here?
• Factions: Having already set the PCs up with faction contacts in LMoP, they enjoyed seeing their factions at work in HotDQ. It also made it easier for me to explain what was happening in many instances by recourse to their knowledge of the factions.
• Objectives: One of the narrative issues for HotDQ is how long it takes the PCs to find out why the Cult is gathering so much treasure. By the end of the first episode it's clear that that's what the Cult is doing, but it can take until the end of the adventure to discern why, and it does take until the end of the adventure to meaningfully stop the treasure train that starts in the first battle. From the DM side, this seems like a lot of excellent foreshadowing. From the PC side, it's a fairly long and convoluted scheme that is somewhat unsatisfying to plod through. ("There's another place this treasure is going? How far are they hauling it?!")
• Realistic Villains: Again, one narrative issue in any campaign is the realism of villains. The villains that were most effective for my group were the straightforward ones: Cyanwrath (the half-dragon champion in Greenest) and Glazhael (the white dragon at the end). The least effective were the ones that (see above) had seemingly inscrutable motives for too long: the Red Wizards, Blogothkus, Rezmir, etc. Indeed, the "helpful" NPCs were much more interesting: the gnome they met on the road and Snapjaw the Lizardman, for example.

 

•  Epic Locales: One thing HotDQ does right is give a (however brief) survey of the Sword Coast and provide some truly amazing locations for the PCs. 
• Pro: A flying castle? That will be talked about for years!
• Pro: A swampy castle with a teleportation circle and a magical telescope wins some points.
• Pro: A dragon hatchery for low level adventurers was a great way to get the dragon-heavy setting early on without a fight with a wyrmling.
• Pro: Even the much maligned "road trip" earns some favor: the encounter with the Golden Hind/Stag is still being talked about months later.
• Con: A roadside fort? Boring.
• Con: Walking through two of the setting's biggest and coolest cities...and doing nothing cool in them? What the heck is the point? Why not just use back-roads?

 With the overall done, I just want to briefly examine the eight episodes and give my strongest thoughts on each. It should be noted that my thoughts below are most useful to DMs looking to run the adventure; players may feel more bored than usual!

Episode 1: Greenest in Flames

Having read a lot to the contrary, I do think that having a giant flying killing machine (blue dragon) and a bunch of raiders attacking Greenest is a great set piece. It was incredibly memorable, and made for a great evening of playing. The major issue was that the encounters simply weren't balanced; they couldn't be because of the flux the rules were in when it was written. Having the party already be level 4 helped a lot, but there were still some modifications that had to be made. Still, saving the keep from the dragon, saving innocents from the temple, and getting refugees off the street were deeply satisfying heroic deeds for my players.

Episode 2: The Raiders' Camp

For some parties, this episode might have been the most fun of all. For mine, it was anxiety causing. This was, once again, an issue of clear objectives: how can we find out what's going on without getting ourselves killed? It's a tough question to answer when no one in the group wants to get everyone else killed by being a ham or asking the wrong question or sticking his/her nose into the wrong tent! Because my players were so reserved, they weren't having the fun of an infiltration but rather the stress of being hunted. There was one hilarious moment however when the party's Rogue (Assassin) had killed a sentry and the sentry's buddy had started meandering over (having heard a noise). With nowhere to hide, she started making out with the corpse; the ruse worked and the guard left her alone. The most puzzling thing for my group (it seemed) was what to do with Leosin; take him at his word, or actually rescue him? The lack of a clear choice bugged them greatly, adding to their stress levels.

Episode 3: The Dragon Hatchery

Again, a lot of modifications would be necessary to run this with lower level characters. Even the fifth level party that was fighting through it in my case found some of the encounters challenging. Weirdly, my PCs didn't find any of the "interesting" reveals until after encountering the dragon hatchery. As a result, finding the maps/intel was anti-climactic. The highlight for them was probably the fight with Cyanwrath. Fully prepared, and fighting with allies, the Paladin who fought him first soundly trashed him this time.

Episode 4: On the Road

Amid the controversy of HotDQ, this episode seems the crux of it all. Some groups loved it and their DMs lovingly and longingly built a more involved framework for the route, stopping with side quests as appropriate. Others (me included) saw running it as a kind of DM purgatory; I pre-rolled all of the random charts/encounters and simply cut out anything that I didn't think the party would enjoy. As much as possible, we breezed through the long, long days of travel with few--if any--encounters. Even the roleplaying encounters were largely brushed aside or "recapped." Rather than try to work in the cultists as spies, I would just say (many days later) that they'd felt like they were being watched. As said earlier, the highlight was the weirdness of some of the encounters: the fungus, the stag, the merchants. Those were fun.

Episode 5: The Carnath Roadhouse

I'm not entirely sure I can convey my dislike for this part of the story, but here it goes: for several sessions, the PCs have been acting like spies. They're imagining themselves as James Bond. Then, they get to the Roadhouse, and the Lizardfolk open the wardrobe to Narnia. Suddenly, instead of being a spy story, it's become a tale of Hogwarts, starting with the station at King's Cross. The problem is that there are no clues left to tell the PCs that the narrative is changing. The result was that the PCs settle in, discover the Lizardfolk are stealing the treasure, and feel like they have to make a choice: follow the Lizardfolk who-knows-where or continue to investigate the Roadhouse. It seems as though the Lizardfolk are some kind of interruption rather than a continuation of the investigation. Thankfully, my group's players were okay to follow the Lizardfolk, but I could very easily see PCs deciding it's the cultists who are far more important to follow than the treasure--after all, the Lizardfolk seem like thieves! There's nothing tying them to the cult except that they've taken the cult's treasure. Maybe I'm just being a grumpy old man, but this lack of motivation bugs me. If done right, this episode should take about five minutes. If done poorly, the PCs waste all kinds of time, earn no xp, find no treasure, and the Lizardfolk get a ridiculous head start. And realistically, I feel like the cunning PCs are more likely to choose the latter; I was probably overwhelming in my support of going after the Lizardfolk to help my party avoid that fate.

Episode 6: Castle Naerytar

Great location. Excellent motivations for the groups/organizations involved. Very difficult to run. I understand that the designers wanted the place to feel like a living and breathing place--one that responds to the actions of the PCs--but it was maddening trying to control all of those moving parts while also running a session. The motivations of individuals were difficult to pin down--and most were written in disparate parts of the book. As a result, I basically had to brainstorm a bunch of different scenarios, keep track of where certain parties would be at certain times, and wing the rest. It worked out, the players had fun, and I think that all the necessary pieces are present (when you include the designers errata), but it's still a pain to run. I think providing one sample path of what might happen and where the individual players might be at a given moment would go far toward helping DMs construct a useful blueprint of their actions. Similarly, having a cheat-sheet (similar to the one in the back of Rise of Tiamat or in the background section of LMoP) would be incredibly helpful.

Episode 7: The Hunting Lodge

Like Episode 5, this felt like the kind of episode that was a side quest which happened to have main quest pieces stuck on it for flavor. If done correctly, the PCs could treat with Talis and be done in minutes. If done poorly, the PCs might be eaten by a troll patrol and never even know where they are. Again, the mission is transitioning; the treasure is so far ahead at this point that it won't be found in the Lodge, but PCs have to pick up on that (or the players do, at least). In the end, roleplaying Talis was fun and (I hope) memorable. It did provide one opportunity to see that the cult's leaders were not slavish pawns, but ambitious men and women.

Episode 8: Skyreach Castle

I loved this episode, but holy cow, so much could go wrong. The PCs could be discovered; any one of the interested parties could betray them; any fight could bring the whole castle down on them; Blogothkus might decide it's easier to squash them than listen to them; Glazhael might eat them; a vampire might eat them; the castle might crash--with them inside it. The list is unending. It's almost past the point of verisimilitude unless the PCs are extremely good at sneaking around and being diplomatic. A party of barbaric fighters and their uncharismatic fire wizard would be dead before they even learned how many enemies they were going to be facing. That aside, the best part of this episode is that the PCs finally start learning what's going on.

Conclusion: In the end, while I do like the storyline being presented, I suspect that Rise of Tiamat will be superior (to run), and I definitely can't wait to do a campaign arc that is entirely contained in one book and which doesn't have the problem of being written while the game rules are still being finished!