Structure and Mechanics: All Them Pesky Rules Bits
You might have noticed that I have barely touched on the mechanics of the encounter, except to briefly mention “an endurance-like” check or “some kind of local knowledge” check. Of course, some of you may already have been reading my example chase scene and saying things like “oh, sure, use Streetwise, DC 15” or “he means a Constitution check with a +2 bonus for the Run feat.” Honestly, except for one little piece of the puzzle which I will get to, the example encounter I spelled out above is pretty much what I would bring to the table. The reason I started this series with the ways to adjudicate actions on the fly is because, once you have that part down, non-combat encounters don’t need a whole lot of other stuff. So, when one of my players says “I want to run up that empty cart, grab the eave, and vault onto the rooftops to continue the chase,” I can just go “give me an Acrojumpclimb check, DC eleventy-two.” or whatever. Because I’m awesome. And I’ve helped to make you awesome too. Just not quite as awesome as me.
So, when you are building your encounters, you focus on the s$&% that matters. Dramatic questions, hooks, conflicts, and decisions. But not everyone is comfortable flying so fast and loose with the mechanics. And that’s fine. You can now run through your encounter, write it up nice, fill in the skill checks for the stuff you’ve decided, figuring out difficulty numbers, and so on. If you’ve got the potential for a fight, put in a stat block. If one of the conflicts is a trap, build and stat that. I don’t need to go through that process and I’ve wasted enough pages.
But, let’s do waste some pages on structure elements and unique rules. I told you earlier to make note of any special mechanics or rules or scorekeeping mechanisms you might need to know how the encounter ends, right? Well, now it is the time to build that. Also, it is now time to build any other special mechanics that might have grown out of the process of filling up the encounter with juicy, juicy decision points.
Structure elements are ways to keep score so you know when it is time to bring your brilliant encounter to a conclusion. Unique rules are fiddly little bits that you think you need to pull off a certain conflict or decision point or whatever.
For example, in the spider encounters, I mentioned the possibility of the heroes driving off the spiders instead of killing them. That is all well and good, but I might want a structure element to tell me when the spiders are “driven off.” Likewise, I might want to give the heroes the opportunity to scare off the spiders somehow. I might spend a little bit of time on a unique mechanical element to make that happen.
It is easy to go crazy with structure elements and unique rules, but you want to keep them as simple as possible and expose the players to as few of them as possible. Players rarely need to see the structure elements unless it helps visually build tension. Even if it does, do not explain the structure elements and how they work except in the most rudimentary way. Never, ever allow the players to play the structure element. Make them play the situation. The structure element is a scorekeeping tool FOR YOU. Likewise, extra bits of mechanics do not have to be explained in detail until they come up, though it is always nice to let players know they have options that might not occur to them.
Structure elements and unique rules should always be as small as possible for the use you intend to get out of them. Most of them will last for one encounter and then vanish. Do not spend a lot of time on them. However, if an element is going to be used again and again, you might want to devote more effort. Be wary of reusing structure elements though. They work best when they are tailored to the situation. Universal rules and structures generally force you to hamfistedly cram situations into rules rather than build rules around situations (see again: skill challenges).
For example, I need of way of tracking the morale or fighting spirit of the spiders, right? Well, I could design a complex mechanical system of morale to use again and again with a bunch of things to keep track of, but that is probably not worth my time. Spiders are going to keep fighting until they are risking severe injury or death. Insects and arachnids are tenacious. So, all I need is a simple rule: when a spider has 10% of its hit points left (or less), it will flee if it can do so without getting further injured. Otherwise, it will keep fighting until it can flee. That’s it. Morale system done!
Likewise, let’s say that once the spiders are below half their hit points, someone could scare them off with an intimidate check or something. Again, simple (I know some games include just this sort of rule, but I’m writing for every game right now) and easy. When a spider gets below half its hit points, I might call out to the player that the spider is growing more hesitant and defensive and they might be able to drive it off. We don’t need to talk about rules or DCs. I just need to tell them that it is possible to scare the spider away. If someone does something clever (“I wave my torch in its face, screaming and shouting at it”), I can give a bonus.
So, structure elements and unique rules should be as small as possible and kept out of the player’s way as much as possible. Remember, all of the rules are just tools for you, the DM, to determine what happens when the players do things. I would love to give a simple set of rules and instructions for building structure elements, but there aren’t any. Not GOOD ONES anyway. Because they are unique, the accomplish what you need them to accomplish, and they don’t get in the way by doing more than that. So, you’ll just have to wing it. You’ll get better at them as time goes on. Have fun. The nice part about them is no one but you has to see them, so no one will know if you do a bad job and have to scrap it.
Ongoing Example: The Chase
I am not going to spell out all of the mechanics of the chase in every given system, but I am going to discuss how I would build the unique elements and the structure element. First, let’s review what I need.
First of all, I need to be able to keep track of the race. Specifically, I need to know when the assassin reaches the finish line. And I also need to know how far from the assassin the heroes are. But, looking at what I’ve come up with so far, I actually DON’T need to know when the assassin reaches the finish line. I’ve scripted the whole chase in terms of where the assassin is going to be. Market, Side Street, Horse Street, Winding Street, Bridge to Crimetown, Crimetown Street, Back Alleys, Crimetown Market. That is eight total scenes or “rounds” of play, right? But maybe I want to stretch things out a little. Let’s say the Market and the Crimetown Street are two rounds, so I have a nice, even ten rounds of play. Why? Because I like round numbers. They are easier to work with. Doesn’t matter. The point is, I know when the assassin gets into the bar because he just keeps chugging away for ten rounds, right? If the PCs don’t stop him, he’s gone.
But I need to know when the PCs are on top of him. For that, I need to measure the distance between the PCs and the assassin. I could do it in feet and consider relative speeds and all that crap, but due to the environment, no one is really moving at their top speed unless they are sprinting. The assassin won’t sprint. He’s pacing himself, navigating, and blazing the trail and he isn’t as hardy as the heroes. So actual speeds don’t matter. So, I just decide to arbitrarily measure the thing in “lead.” How much of a lead does the assassin have?
You know what’d be neat? If I had a visual aid. Suppose I marked off a piece of paper in spaces and put the assassin at the end. Each space represents some arbitrary amount of lead. If I don’t want a visual aid the players can see, I can just use numbers. PC 1 is 8 spaces behind the assassin. PC 2 is 5 spaces behind the assassin. And so on.
Each time the PCs take an action to increase their speed relative to the assassin, they move ahead a space. Each time the PCs take an action that requires them to stop (firing an arrow, throwing a spell, climbing up to the roofs), they lose a space. Simple as that. Again, the players don’t need to know these rules. It is helpful to see the visual aid, but they shouldn’t be playing the visual aid.
If all the heroes drop off the back of the chase (more than 10 spaces away), the assassin escapes. Moreover, if the assassin reaches Crimetown (across the bridge) and no one is in the front half of the board, he tries to vanish. The heroes each get a tricky check to spot him, but if they don’t, he vanishes. The same occurs in the Crimetown Back Alleys. If anyone is on the rooftops, they get a big bonus on the check.
That seems pretty reasonable. So, how much of a lead should the assassin start with? Well, we want him to be catchable, but ideally, we want him to be catchable near the end of the race. What is the minimum number of spots someone can speed themselves up?
Twice in the Market, sprinting on the Side Street, Sprinting on the Bridge, Twice sprinting on the Crimetown Street, and once in the Market, right? As written those are where the heroes have nice, obvious ways to speed up. That’s seven opportunities. But we don’t want to require them to hit all seven. We want to allow for a few failures. So, let’s require five. The assassin starts five spaces ahead of the party.
And that pretty much covers the basic structure of the encounter. Except, what about the person on the roof, if there is one? His main role is to be the spotter. He’ll save the day if the assassin has a lead on the party in Crimetown. And he gives the party opportunities to choose to stalk instead of chase if they think of that. But what else.
Firstly, climbing onto the roofs costs a space. The person isn’t chasing. They are staying still. But suppose, other than that, they automatically gain a space every round as long as they can manage an Acrobatic type check. If they fail the check, they fall to the ground, take damage, and lose a space. If they succeed, they gain a space. So, if someone climbs up on the roof in the first Market spot (right away), they are six behind, then five in the Market, then four in the Side Street, then three in the Winding Street, than two when the party hits the Bridge. Then, if they can dismount the roofs successfully, they can sprint in the next three spaces and win. That works really well. We’ll add a rule about dismounting using an Acrobatic check to hit the ground running and not losing any ground.
Of course, on the other side of the bridge, they can reclaim the roofs at the cost of a space and keep gaining ground for a flying tackle. That’s also cool.
Now, what about actions that slow up or injure the assassin. Someone is going to try to do something to the assassin: shoot him with a weapon, cast a spell, throw a rock, yell ahead for the crowd to stop him, something. We’ll allow any of those actions that seem reasonable and we’ll have them cause the assassin to lose a space which effectively means everyone else gains a space. Of course, most of those actions require one of the PCs to give up a space.
As for sprinting, it really doesn’t require too many mechanics. We’ve limited it with the environment and we’ve made it an important way to win the chase if one doesn’t use the roofs or the secret back route, so we don’t need to make too many elaborate rules. We’ll require some kind of endurance check for it, but let’s make it risky too. If the person fails by a certain threshold (say five or more), they fatigue themselves, slow down, and lose a space. It is important that we do this so that the party can lose ground.
For that matter, we can also decide that someone who stops to save the crowd from the horse or to rescue the drowning guy on the bridge drops completely out of the race. So we can eliminate a couple of PCs to up the stakes. And, when the assassin sets the rampaging horse lose, if the PCs ignore the horse, they all need to make some sort of saving throw or lose a space avoiding the horse.
In point of fact, we probably want to make every attempt to speed up (like dealing with the crowd in either of the markets) cost a space if they fail, just to keep things shifting back and forth and add some excitement. It is a little more advanced topic, but “survive until the finish” is less interesting than “push for victory or be defeated.” In general, you want opposition not just to prevent the PCs from winning, but to push them toward losing. That makes it feel like more of a conflict.
Also notice that the encounter has a number of different endpoints, even if it doesn’t appear to at first glance. If the heroes catch the assassin, they can interrogate him. If they stay close enough to the assassin, they follow him to the tavern where he hides out. They can search the place and try to turn him up or stake it out. If they stay a little farther away, they have a rough sense of the neighborhood he is hiding out in when he vanishes into the back alleys and can start canvassing the neighborhood. This is an important thing to pay attention to when building an adventure. It also means I don’t have to worry too much about balancing every number in the encounter. As long as I get it close enough, the heroes will probably end up with some degree of success.
At this point, we have just about everything we need to make an exciting chase scene work. All that is left is to clean it up. Now, I am not going to give it a complete writeup, but I will spell out the basics for you. Keep in mind, as you read it, that I purposely built a big, important encounter. This is not some middle-of-the-adventure diversion. I wanted to really show off the biggest, most powerful example of a chase that I could. This baby would start off an adventure. Maybe even a campaign arc. It isn’t often you build one this big and complex.