Thursday, February 20, 2014

The physics of magic and the wizard's stats

A wizard conjures a magic missile, fires it off and hits without even rolling to hit and without any recoil. The hail of stones rushes forward from the mage's hands. A lightning bolt strikes out from his fingers. All of this without any apparent physical effect on the sorcerer. Why?

Isn't that magic missile pushing against something as it is sent forward? For example the magic user's body, in the same way a rifle pushes against the shooter's shoulder. Non inertial magic is a term I'm using to refer to all that magic we love to use which has no physics to explain how it comes to be (which is fine, it's magic), but also has no physics to explain how it affects or doesn't affect the environment around it either.

What would the effect be if certain types of magic had inertia? Sure you can conjure a rock, but quite another thing is to throw it. Sure, magic can work as a hydraulic system, empowering your body, but there has to be some underlying strength. Factor in the strength in such a spell. The rock's weight can't be any arbitrary number, but rather a multiple of the wizards strength not his intelligence or wisdom.

Got a lightning bolt? Sure, but those six plus digit voltage levels are going to have an ionizing effect on anything nearby, including the magic user. Consider constitution or endurance. Even some "temporary" off the record hit point loss that represents the "ionizing damage" the bolt does to the wizard. These "pseudo" hit points hit zero? No more lightning bolts until they're recovered.

Want to invoke a daemon with low charisma? Good luck with that. The creature may be summoned and under the wizard's control, but flattery will still go a long way in granting you what you want.

Although I've seen some games include more than intelligence or wisdom into the "magic equation", it is not a common practice across the board and magic remains pretty much "non inertial". There is seldom any negative feedback rule a magic system or some sort of diminishing return model that may lead to a capped power growth for magic users. The magic user just keeps growing and growing usually based on one stat and at best sometimes two.

What do you think? Do you believe magic users have it too easy just relying on one or two key attributes and having everything else work like magic (pun intended)? Or should more attributes and values be taken into consideration when developing magic rules and spells? Would this help solve the exponential vs linear power growth many of us complain about?

Here are some ideas I'd like to put forward

  • If your game has spells organized by spheres or groups, relate an attribute to each and require higher attributes to use such a sphere. Even have magic that doesn't require high intelligence or wisdom. Some instinctive power of a tribe that relies on other attributes. 
  • Factor in attributes into the spell. How effective a spell is depends on other attributes aside from intelligence. A fighter, due to strength or endurance, can be more effective with a spell through a scroll than a magic user of considerably higher level. A rogue, due to agility, a can perform a task better with a ring than a magic user of a higher level.
  • If you're considering failure mechanics in your spell system then relate these to attributes as well. A spell that requires agility may be more prone to failure if the magic user isn't nibble fingered. The aforementioned lightning bolt may be more prone to injure the magic user if he has low endurance.

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Sunday, February 16, 2014

Poor Death Star Design

There's an open letter from the Death Star's designer Dak Exhaustport explaining why it wasn't his fault the Death Star was destroyed by a group of small fighters. While I do understand his concern regarding the 90° turn at the vent entrance and I too find it suspicious. I have to challenge his claim that he is without fault. It is true that there was a conspiracy to destroy the empire. It was clearly being carried out by Anakin Skywalker and his son Luke. Clearly it was meant to exploit the emperor's desire to bring Luke to the dark side and it was meant to take place when they met and not sooner. Unfortunately the whole Death Star thing blew up in Darth Vader's face and he had to postpone the meeting between Luke and the emperor.

Now back to the Death Star vent port issue. Dak Exhaustport claims it isn't his fault. That other issues lead to the exploit of the vent and not his lack of foresight. I say that it is not only a design which exposes the battlestation's core to a fighter attack, it is also a very inefficient one. Even for Earth's standards nowadays. Let me present exhibit A. It clearly shows the vent port going from the surface straight to the core. Literally straight to the core.

So while I do admit it is possible to use the force to turn the torpedoes 90° at the entrance of the vent, it would have been impossible to guide them through a maze of turns all the way to the core. The force is strong with Vader and Luke, but without visual sight it would be impossible to guide regardless of their skill with the force. This leads me to exhibit B, C and D.

Exhibits B and C show modern day Earth ventilation designs in which turns are clearly visible. Hot fumes can easily handle turns in the ventilation system. If Dak Exhausport had placed a few turns in the shaft as it lead down (or up, however you see it), the Death Star would still stand.

The design was also a poor one as Exhibit D shows how one shaft usually terminates. It fans out to a set of actual ports that provide even ventilation to the area the vent is meant to cool. So we would expect the controversial vent to fan out as it approached the core. This makes sense because a single port would be able to cool the area in its vicinity, but not areas in the opposing side. This would lead to thermal differences within the core. If the vent fans out into a set of vents around the core the overall effectiveness of the vent system increases and removes the possibility of a torpedo reaching the core.

So though there is the aggravating circumstance of the whole Skywalker conspiracy, the fact stands that Dak Exhaustport is entirely responsible for the destruction of the Death Star. Not only is it a poor vent shaft design as shown by exhibits B to D. It is also on that leaves the whole battlestation susceptible to external attack by a lone fighter pilot.

Exhibit A

Exhibit B

Exhibit C

Exhibit D

Image sources's_Technical_Manual_blueprints.jpg

Thursday, February 13, 2014

The calendar as a story element

The calendar plays an important aspect in our lives. It tells us when winter or summer occur. When to plant and when to harvest. It marks certain days to celebrate, commemorate and hold ceremony. Now we usually run on a 365 day calendar, but what if we had two calendars and they weren't the same length. These two calendars are in turn broken into smaller elements which fit together as gears in a machine. Each tooth of each gear means something and as they turn they unfold the destiny of men. Such is the nature of the Aztec calendar. The ultimate random encounter table.

The largest of these set of gears is the xiuhpohualli (year count) a calendar year of 365 days. It is composed of 18 months (metztli) of 20 days each and 5 dark days called nemontemi. The tonalpohualli (day count) is a smaller set. A 260 day ritual calendar comprised of 20, 13 day periods, called trecenas. The xiuhpohualli (year count) and tonalpohualli (day count) spin together giving a year count and a day count for every day in a man's existence. They spin and spin in a cycle that repeats itself every 52 years. A century for the Aztecs sometimes called the calendar round.

The days in the tonalpohualli (day count) each have a name of either an animal or object which indicated what influenced such a day.  Some sample name are house, lizard, death, water, grass, and monkey.  These days also have a cardinal direction (north, south, east and west). Together these elements carry strong omens and meanings to those born in such days, those wishing to marry, venture on trips, build a house or make war.The cardinal directions were related to gods and held their own symbolism. The East to the God of Rain: Tlaloc, life and fertility. The East was the start of the Sun's travel. The West belonged Chalchihuitl, the Goddess  goddess of water, rivers, seas, streams, storms, and baptism. The West also marked the end of the Sun's path. Mictlantecuhtli, the God of Death, Power and Force, owned the North. The South was Xochipilli's, the prince of flowers, god of love, games, beauty, maize and pleasure.

For example, a dire time to travel was the first day of the five western trecena, (1 Deer, 1 Rain, 1 Monkey, 1 House, and 1 Eagle). On those days the dreaded vampire like Cihuateteo would roam road crossings. Stealing children, causing illness and even attacking weary travelers.

Thirteen of these days build up a trecena. There were 20 of these in a tonalpohualli (day count). Each one of these 20 trecenas was associated with a particular deity. These deities held power over these days, sometimes for good and sometimes for ill.

All of this in turn fits into the 365 day xiuhpohualli (year count) calendar, which had it's own days and months! Can you see how the mother all of random encounter tables begins to build up? What fortune will this day bring to the party? Well what god influences the xiuhpohualli month and what god the tonalpohualli trecena and what day is it? Is it a north, east, west or south facing day? Is it a benevolent god? Are we in the dreaded last 5 days of the xiuhpohualli. If so, let's stay in the tavern a few more days.

While two interwinding calendars may be too much for some, a simpler model can be built to add flavor to your setting and particularly your clerics. In your campaign you can set up months and days with each of the important deities, the good and the bad. The meanings for each day. As the gears spin and spin they crank out new paths for the adventure. Giving a good day to travel once then an ill day for a journey at some other time. Calendar dates may put pressure on the party. They have to reach their destination before the end of a certain 13 day period or depart during a certain month. Even small daily omens can help resolve what kind of creature the party will meet and what fortunes lay ahead before sun sets.

If you want to see this in action I strongly recommend the following site. Punch in today's date and read the significance of this day in the Aztec calendar.

For deeper look into the Aztec and Mayan Calendar take a look at the following:

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Tuesday, February 04, 2014

Opposing die rolls

As players we are used to rolling to beat a target number with our dice. What I've been looking into and using in my games recently is rolling dice to beat a difference between dice. So instead of rolling 14 on a d20 or higher you need to have a difference of 5 or higher between two d20s. How does this work and how does it affect the game?

How does it work? Simply put the player rolls dice and the GM rolls dice. What matters is not the value each one rolls, but rather the difference between these rolls. To make a simple example lets play with d10s. A task has to be solved and the GM sets the difficulty at 5. To succeed the player and GM roll a d10. The difference between the rolls has to be 5 or greater to succeed.

The odds for a d10 - d10 is the following:

Since we are only concerned with the difference and not which is higher we must consider the absolute value of the die roll as show in the following graph:

Why has this caught my attention lately? Well for starters lets look at more complex dice. Look a the d20 vs d20 and 2d20 vs 2d20 below. The 2d20 vs 2d20 gives a nice flat curve towards the higher values. This means high difficulty tasks are going to be very improbable to succeed at unless the character has a lot of skill.

For example if the task requires a 32 or higher difference between the rolls the odds of success are minimal. If the character has just a +3 from skill the odds don't budge the slightest. On the other hand a character with +10 bonus would get considerable benefit, he's an expert. Yet this might not be enough to ensure an acceptable degree of success. Come in team play. Since there are a lot of values (0 to 38) it is easy to implement a mechanism for team play and group cooperation. If 4 characters all add their +4 to the task thats +16. It drops the difficulty from 32 to 16, making a task with 0.5% chance of success into one with 20% chance of success.

Finally the thing I really like, and that's because I'm a wicked GM, is that this keeps the players guessing. I don't have to reveal my roll and since there's no target value they're left guessing if they succeeded or not. Specially in the easier tasks. If the task is hard, once again taking the 32 difficulty rating as an example, it's pretty obvious from the player's roll which option is a winner and which one isn't. This is similar to real life, if the task is hard and you're not very experienced you don't raise your hopes up of having a success and you pretty much know you blew it. On the other hand if the difficulty is 10, there are a lot of values that I can roll as a GM that will give them a 10 or greater difference. The player rolls a 15, and well a 0, 1, 2, 3, 4, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37 and 38 on my roll would mean failure. What did I roll? Did I roll these less probable values or the more probable ones between 5 and 25? Time to open the treasure chest and find out.

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