by
Mike Mearls
Writing
The Book of Iron Might
was an exercise in gambling. This isn't just a cheap excuse
to justify my recent trip to New Orleans as a business
expense, but an insight into the design process behind
it.
If
you've ever been to a casino, you probably have seen a
slot machine. The slots are, in my opinion, the goofiest
way to waste money. These machines are designed, programmed,
and built for you to lose. But they offer that hope that
this time you'll beat the odds, and that hope is exactly
what gets suckers into casinos in the first place. The
guys who design these things are pretty sharp, because
most slot machines allow you to wager almost as much as
you're willing to put on a single pull of the lever. You
can wager 50 cents, or throw down five bucks on a single
play. The more you wager, the more you lose.
Sorry!
I meant to say, "The more you wager, the more you
might win."
Anyway,
there's a big risk-reward mechanism built into gambling.
The greater the risk you are willing to take on, the greater
the reward you stand to reap. That basic principle forms
the foundation of The Book of Iron Might's maneuver
system. If you're willing to take a massive penalty to
your attack, you can attempt to deliver a strike that
knocks a foe prone, disarms him, and deals extra damage.
At
the time I designed this subsystem, this struck me as
a tremendous insight into game mechanics. You normally
can't assume this sort of risk in d20. It's a binary system
-- you either meet a DC and succeed, or you miss it and
fail. There's no "sort-of failure" or "partial
success" in d20, unless you use a skill check variant
that requires you to succeed X number of times at a check
to complete a difficult, long-term task. The Legend
of the Five Rings system featured something similar
to a risk-and-reward mechanic with raises, but I never
had the chance to play that game. However, the basic idea
sounded like a lot of fun. If you take a penalty to an
attack, you get the chance to do something cooler than
normal. I liked the feel of it, and I played around with
it in a short game I ran for a few friends.
My
enthusiasm ground to a halt when I realized that the penalties
could make it impossible for an attack ever to hit. As
you gain levels, the monsters you face have a higher Challenge
Rating. With that CR usually comes a higher Armor Class.
Thus, no matter what level you might be, a -5 or -10 to
an attack is enough to cause you to miss almost every
time you attack. That's not much fun, is it? What's the
point of all those cool benefits, like knocking an opponent
prone, or forcing him to move, if your attacks never connect?
Enter:
The Drawback
The answer proved to be simple, and like many of the mechanics
I design, the inspiration for it came from beyond the
realm of roleplaying games. In Magic: the Gathering
there are plenty of cards that give your opponent an advantage
in return for the benefit the provide you. You might have
to sacrifice a creature you control to put a spell into
play, or your opponent may gain life. To keep d20 special
maneuvers balanced yet usable, they could grant your opponent
a benefit. After all, the core maneuvers such as trip
and disarm already do that. Why not just follow that pattern?
Thus, the idea of drawbacks was added to the maneuver
system. You could reduce the attack penalty a maneuver
inflicts by provoking an attack of opportunity, suffering
the maneuver's effects, or making an attack that leaves
you prone.
The
hard part in the design was figuring out the penalties
I had to glue to each maneuver benefit and the reduction
in the penalty that each drawback would give. I decided
that I wanted -5 as the minimum penalty. That's a big
enough drawback that even a fighter with a good base attack
is going to notice it. In my worst nightmares, the maneuver
system would make it possible for characters to always
make attacks with special benefits without any real reduction
in their ability to hit a target. If you can always attack
and knock an opponent prone, why ever bother with a plain
old attack? Thus, the minimum penalty to the attack had
to be steep enough to have a noticeable effect on the
game.
With
that basic framework in place, the rest of the system
was easy to design. For the effects, I just cracked open
the core rules and wrote down every possible condition
that a character can gain, from fatigued to nauseous.
I tossed out all the ones that didn't make any sense for
the subsystem and designed rules around the ones that
were left. In a few cases, I cannibalized special maneuvers
already built into the system, such as disarms and bull
rushes.
The
drawbacks underwent a similar process. Starting with the
core special attack actions, I extracted the disadvantages
that they inflicted on an attacker. Attacks of opportunity
were an obvious choice. Drawing on the special attacks,
they can come from either your target or everyone who
threatens you; in some cases, they can ruin the maneuver
before you have the chance to attack. The more you want
to reduce a maneuver's attack penalty, the more serious
the drawbacks you must take on.
In
the end, I think the maneuver system has proven so popular
(judging by our sales numbers) because it does something
that people always wished they could do in d20. Sometimes,
standing in one place and hacking at an opponent can grow
boring, especially if you've just watched a bunch of action
movies. A roleplaying game designer's goal is to take
a system and make it better -- more fun and interesting
-- than when he found it. Hopefully, The Book of Iron
Might will have that effect on your game.
Next
time, we'll talk about the ironborn. Until then, good
gaming!
