#RPGaDay2020 Day 11: "Stack"
The picture at the top of this essay is a puzzle called the Tower of Hanoi. It's a stack of disks on one stick, and you have to move the disks to another stick such that:
- They end up in the same order (smallest to largest)
- You only move one disk at a time
- You can never put a large disk on top of a small disk.
Thus the whole puzzle is about stacking effectively, to achieve your outcome--and this ties directly to this essay, which is different than many of my other essays. Instead of talking about my world, or my game running or game playing philosophies, I'm actually going to look at a specific element of game design and how I've worked with it over the years.
Bonus Stacking in RPGs
One of the problems that all RPGs struggle with is scalability. Mechanics that work for starter characters don't necessarily hold up for mid or high tier characters. My favorite example of this is a 3.X D&D skill which suggests that a roll of 25 will get you a wizards secret childhood name. Given that you are rolling a d20 on the skill test (average of 10 or 11) this sounds pretty hard--something you'd only get rarely. But depending on which system you are playing in, succeeding at a difficulty 25 roll may be impossible or trivial, depending on the mechanics of the game.
One of the biggest culprits of scalability problems is the concept of stacking. Do multiple bonuses combine to give you an even greater bonus, or are you limited by the best, or can you even apply bonuses from one source on top of something else?
The essence of the problem is that as characters gain abilities,levels,etc, the players generally want to them to become better at the things they can do--which in turn allows them to take on greater challenges. This is natural in concept...if you perform a task for your "10,000 hours" you should obviously be much better at it. But how much better should the characters actually get, and how do other factors (magic, personal abilities, etc.) help boost their abilities are game design decisions and trade-offs that creators have to make.
How it looks in 3.x D&D
When 3.x allows you to stack bonuses line up, the very hard can suddenly become easy. The worst stack breaking that I've seen in 3e D&D was the Arcane Archer. At the time, they got magic arrows that got better as they leveled up. If they invested in a magic bow, the bow bonus stacked with the arrow bonus. So a reasonably big arcane archer could easily be walking around with +4 arrows, +4 bow, +12 Base Attack Bonus, +6 Dexterity Bonus and a +1 specialization bonus--giving them a +27 to hit, and a +16 damage per arrow--and that's if I'm not forgetting something else that stacks. Such bonus stacking is great when Bard Bowman takes down Smaug with one arrow, but is annoying when you're trying to craft encounters that challenge the players. (Remember that 25 was the target to know a wizard's childhood nickname, and this is +27 to hit on TOP of their d20 roll to hit.)
Both 3e and 3.x D&D had the concept of bonus "categories". And the idea was that if you had two bonuses from the same category they would not stack--you would just take the better of the two. This was great in principle, but in reality there were numerous categories, and it was not that hard to find stacking combinations, which would break play. So +1 luck, +1 dodge, +1 morale, +1...and suddenly you have a +5 bonus just by stacking a bunch of small bonuses. For this reason, I really considered D&D 3.x to become difficult to run at around 14th, before challenging the players became too difficult without getting contrived or getting into "save or die" situations.
Part of the issue in the case of the Arcane Archer is that this is what they do...so their bonuses line up well pretty much every time they're called on to do their thing. So in addition to be a somewhat broken mechanic, it's also ubiquitously available to the character.
This is the system I play most often (because Trinity is based on 3.x), so I have the most experience in dealing with the stacking issues. Credit to the WOTC team, as 3.5 certainly helped by cleaning it up. But it's still a problem and in terms of managing to it...my first appraoch is to keep the game between 5th and 12th level for as long as possible. This is what we call the "sweet spot" where characters feel powerful, but don't break the game.
Beyond that, I try to throw new and different situations at the players. I throw challenges or opponents at the players that require an athletics check (or similar) that everybody needs to eventually make to continue on or avoid pain. The key is to keep people on their toes, without making them feel continuously "nerfed."
Changes in 5e D&D
5e changed that dramatically by saying that at a given level you had a base bonus to apply to literally anything you did, and that would stack with most other things once. This was neat in that it took some of the traditional bonuses, and kept them reasonable--so at higher levels, the bonuses are not so absurd as to guarantee success...but you can still differentiate yourself. The flipside is that at low levels, there's almost no differentiation between characters. Someone who has chosen to learn Intimidate has a +2 advantage on somebody who didn't take that skill...sure it's an advantage, but about 40% of the time, the completely unskilled character is going to be more successful than the skilled character.
Cypher System's Handling
Cypher System handles things differently. Everything is assigned a Difficulty target of between 0 and 10, and the die roll needed to achieve the target is 3x that (so 0 to 30.) Your player lowers that target difficulty by the application of skills (up to 2 points out of 10), effort (up to 6 points out of 10, but it's very expensive to do so) and assets (up to 2 points out of 10.) So in theory, if you are a top tier character, there will be difficulty 10 trials that you can make automatically by lowering the difficulty to zero.
Unlike the Arcane Archer example, the bonuses CAN stack impressively, to turn the impossible into the automatic, but only in certain circumstances and at a willingness to pay the very high effort cost. So in reality, it doesn't happen that often. In other situations, the high level characters actually appear no different than a low-tiered character for those circumstances they aren't trained in.
I say that I write these essays for myself, and that's true. In this case, the essay was a chance to put a bunch of thoughts I'd had over the years into a single spot. Every designer has to deal with these things, as I mentioned, and I credit them all for the successes they did have---even if players find ways to "break" the system. In this case, the fundamental D&D leveling system encourages players to get better over time, and so to stack their abilities in a way that would make Sun Tzu proud.