The Importance of FATE

Add FATE Points and Stir

The previous article talked about setting up and testing a basic Monte Carlo model of FATE combat. This one tackles the task of introducing FATE points to the model. Most of the article covers testing and optimizing the model. Readers not interested in finicky details of model building are really encouraged to skip to the Results section at the end. Seriously, it’s ten pages of details, just look for the picture of fudge dice.

FATE point mechanics

While different versions of the mechanics change things up a bit most FATE systems use FATE points. FATE points are a limited pool of points that can be spent for a number of different bonuses. However, in order to spend a FATE point the character not only needs a FATE point but needs an appropriate Aspect.

Aspects are character abilities that are usually a phrase or description like “Veteran of Normandy” or “World’s Greatest Mechanic”. In order to use a FATE point in a situation the character has to have an Aspect appropriate to the circumstance. So a “Veteran of Normandy” could spend points on combat rolls or getting along with other veterans while the “World’s Greatest Mechanic” could spend points repairing things or to have a special gadget rigged up in their car.

Any number of FATE points can be spent on a roll within two limits. First, the character has to have the points. Second, only one point can be spent per Aspect on a given roll. So a character with “Crack Shot” and “Veteran of Normandy” could spend two points on a roll to shoot someone but without a third applicable Aspect couldn’t spend three.

Several different bonuses can be purchased with FATE points. Most iterations allow some world editing like declaring that one of the character’s war buddies is in the bar in the middle of nowhere. In terms of dice rolls players can usually choose between rolling the dice again or simply adding +2 to the roll. Obviously, which of these is preferable depends on the original roll. Adding 2 to a roll of -4 only gives a total of -2 while rerolling will give -1 or better over 4/5 of the time. In contrast, adding 2 to a +3 roll gives a total of +5, more than any roll can ever yield. Table 1 shows how a reroll compares to just adding 2 for different original rolls.

Table 1. Comparing Rerolling the Dice to Adding 2

Roll	Chance Reroll Better (%)	Chance Reroll= +2 (%)	Chance +2 Better (%)
-4	81	12	6
-3	62	20	19
-2	38	23	38
-1	19	20	62
0	6	12	81
1	1	5	94
2	0	1	99
3	0	0	100
4	0	0	100

For very low rolls, -4 or -3, rerolling will generally give better results. For moderate rolls, -1 or better, adding 2 is generally the best plan. At -2 the average results are the same and the choice would depend on how much randomness a player wanted.

Model Assumptions

The huge number of variables shows why I’ve been trying to avoid FATE points. How many points does the character have, do they have the right Aspects, reroll versus add 2, spending multiple points on the same roll, etc. In order to put this in a program some pretty restrictive assumptions needed to be made and so the results will at best be an approximation of the effects of FATE points.

For ease of handling, the model assumed that the characters had appropriate Aspects but would never spend more than one point on a single roll.

Then there was the question of which rolls to spend the points on. The model could easily separate out attack and defense rolls so was able to take a look at only spending for attack, only spending for defense, or both attack and defense.

However, it also needed a criterion for when to spend points on these rolls. For attacks, missing by 1 is just as much of a miss as missing by 3. Because of this it seemed likely that only increasing rolls that were already pretty good would yield better results. So the model used a cutoff for spending on attacks. Only rolls making the cutoff or higher caused a FATE point to be spent. For attacks this was always adding 2 to the roll, since rolls of -4 or -3 wouldn’t really meet the criterion for pretty good roll. The opposite is true for defense rolls. Once damage is 0 increasing the defense roll is meaningless. Ok, for aficionados, some versions of FATE have a special bonus for beating an attack roll by 3 or more but I didn’t worry about that. So the model used a cutoff for spending on defense. Only rolls making the cutoff or lower caused a FATE point to be spent.

Timing can be very important for spending FATE points. Spending the character’s only point to reroll a -1 defense roll may seem a poor choice if the next round they roll a -4. However, it’s a program and so the choices needed to be hard coded. It was set up as a first come, first serve model so points were spent whenever they were available and a roll made the cutoff for FATE point use. Since the program made attack rolls before defense rolls this also meant that attack rolls took precedence over defense rolls in a given combat round.

Testing and Fine Tuning

Attack!

Because the attack algorithm of always adding 2 was so simple, I started testing with attacks. The first test was to see whether adding in FATE points for attacks was symmetrical. If both opponents were given a FATE point they should have equal chances of winning the fight. Figure 1 shows the results for 1 FATE point each with an attack cutoff of 0 or better and, as expected, there was no bias between the opponents.

Figure 1. Equals Attacking with 1 FATE Point

Like increasing attack values over defense, using FATE points to increase the attacks should shorten combats. 1 FATE should produce a shorter fight than no FATE points though not as much as setting attack skills 2 points higher than defense, which would be like using a FATE point for every attack. This is confirmed in Figure 2 which shows that using FATE points to increase attacks shortens the fights.

Figure 2. Attacking with FATE Shortens Fights

The next question was where to put the cutoff for attacks. Changing this should have little effect when both opponents had FATE points so the test was run with Pain having 1 FATE point for attacks and Suffering 0. Table 2 shows that the optimal choice for opponents of equal skill is 0, though the differences are generally very small. Flipping the number of FATE points flipped which opponent had the advantage, but the advantage was unchanged indicating no bias in the model.

Table 2. Attack Cutoff for Equal Opponents

Attack Cutoff	Pain Wins (%)	Suffering Wins (%)	Ties (%)
-2	54.0	40.1	5.9
-1	54.5	39.7	5.9
0	54.6	39.5	5.9
1	54.1	40.0	5.9
2	52.4	41.7	5.9
3	49.7	44.4	5.8

Defense

With attacks working as expected the next step was to test using FATE points for defense. I started with a system that used rerolls for any roll of -4 or -3 that made the defense cutoff and +2 for any roll -2 or higher that made the cutoff. Once again symmetry between the combatants was tested. Each opponent was set to equal skill and 1 FATE point to be spent only on defense with a 0 or lower cutoff. As seen in Figure 3 there was no bias between the opponents.

Figure 3. Equals Defending with One FATE Point

Just as FATE points for attacks shortened fights, FATE points for defense should lengthen them. Figure 4 shows a comparison between no FATE points, 1 point spent for defense, and setting attack skill 2 lower than defense skill. As can be seen spending for defense increased the length of the fight.

Figure 4. Defending with FATE Lengthens Fights

Next came the question of cutoffs for the defensive roll. Also, how the dynamic system of rerolling or adding 2 depending on the original roll fared against always rerolling or always adding 2. As with attacks, Pain was given 1 FATE point and Suffering 0 and the simulation run for different cutoffs. Table 3 shows that the optimal defense cutoff for equal skilled opponents is -2. As expected this is a lower cutoff than for attacks. However, comparing Table 2 and Table 3 shows that spending on defense seems to win more fights.

Table 3. Defensive Cutoff for Equal Opponents

Defense Cutoff	Pain Wins (%)	Suffering Wins (%)	Ties (%)
-3	53.5	40.9	5.6
-2	55.5	38.9	5.6
-1	54.8	39.5	5.7
0	53.4	40.8	5.8
1	52.4	41.8	5.8
2	51.8	42.4	5.8

I also compared the algorithm of rerolling for -4 or -3 and adding 2 for higher rolls with always rerolling or always adding 2. As expected, the algorithm performed better than the other strategies.

Both Attack and Defense

The next test was to run fights with the option of attacking and defending with fate points. Both combatants were set to equal skill and 1 FATE point using an attack cutoff of 0 and a defense cutoff of -2. The results confirming symmetry are shown in Figure 5.

Figure 5. Equals Attacking and Defending with FATE

It should be noted here that the model used in this and the previous article is the second version of the model. The first version failed this test. That model calculated one set of attack and defense rolls and then the other set. The result was that Pain would decide on whether to use FATE points for attacks then defense while Suffering would decide on defense and then attacks. Given the limited pool of FATE points the timing of the choice mattered and the results were not symmetrical. The new version decides for attack and then defense for both combatants.

This shows the importance of running tests on the model. Also, it shows how subtle an error can be. When no FATE points were used or they were used only for attack or only for defense the original model worked just fine. The timing error only showed up when testing both attack and defense.
Given the availability of both attack and defense bonuses it was unclear what affect the FATE point would have on combat length. Figure 6 compares spending for both attack and defense to no FATE points as well as FATE only for attack or only for defense.

Figure 6. How Attacking and Defending Changes Combat Length

The results mostly resembled that for attack only use of FATE points. The reason became clear when I tried to determine the optimum cutoffs for the combined attack and defense. Running through all the possible combinations from -4 to +4 for both variables would have been too time consuming so I looked at permutations around the previously determined cutoffs. Defense cutoffs of -1, -2, and -3 for different attack cutoffs were tried as well as different defense cutoffs for an attack cutoff of 0. Table 4 shows the results with the best results for any given attack cutoff shown in red.

Table 4. Combined Attack and Defense Cutoffs for Equal Opponents

Attack Cutoff	Defense Cutoff	Pain Wins (%)	Suffering Wins (%)	Ties (%)
-2	-3	54.0	40.1	5.9
	-2	54.1	40.0	5.9
	-1	54.0	40.1	5.9
-1	-3	54.5	39.6	5.9
	-2	54.6	39.6	5.9
	-1	54.5	39.7	5.9
0	-4	54.7	39.4	5.9
	-3	54.8	39.3	5.9
	-2	54.9	39.2	5.9
	-1	54.8	39.3	5.9
	0	54.4	39.7	5.9
	1	53.9	40.2	5.8
	2	53.7	40.5	5.9
1	-3	54.6	39.5	5.9
	-2	54.7	39.4	5.9
	-1	54.5	39.6	5.8
2	-3	53.9	40.2	5.9
	-2	54.5	39.7	5.8
	-1	54.3	39.9	5.8
3	-3	53.5	40.7	5.8
	-2	54.9	39.4	5.7
	-1	54.4	39.8	5.7
4	-3	53.5	40.9	5.7
	-2	55.5	39.0	5.6
	-1	54.7	39.6	5.7

The first thing to note is that the best value for defense only, 55.6% for a -2 cutoff (Table 3), is higher than the highest value, 55.4 for a 4 attack and -2 defense cutoff, in this table. A mix of using a single FATE point for both attack or defense is not as good as using it solely for defense. Consistent with the defense only cutoff calculations, the best values were obtained for a defense cutoff of -2 or lower.

One odd result was that at a defense cutoff of -2 there were two maximums for the attack cutoff. This is probably easiest to see as a plot.

Figure 7. Mixed FATE Use at Defense Cutoff -2

This appeared to be the result of the superposition of two effects. One is the optimal attack cutoff of 0. The other is that using the point for defense gave better results. Thus when the attack cutoff became strict enough that the point was more likely to be spent on defense than attack, a cutoff of 3 or higher, the percentage wins started to rise again. An attack cutoff of 5 or higher, which could never be rolled, would be the equivalent of spending only for defense. Note that this also explains why in Figure 6 the attack and the attack and defense curves are very similar. With a defense cutoff of -2 and an attack cutoff of 0 the program was much more likely to spend the single FATE point on attack than defense and so the curve was very similar to the attack only curve.

Results

After that overly long preamble, here are the results. Keeping in mind that these results are an approximation, Table 5 shows the percentage chance of winning a fight against an equal skilled opponent with different numbers of available FATE points. The table shows results for using FATE points only for defense, only for attack, or for both, though at most one point on any roll. The results are shown graphically in Figure 8.

Table 5. Effectiveness of FATE Points in an Even Fight

Fate Points	Attack Only (% wins)	Defense Only (% wins)	Both (% wins)
0	47.1	47.1	47.1
1	55.6	54.7	54.9
2	62.2	62.8	63.3
3	66.7	70.7	71.2
4	69.3	77.5	78.2
5	70.5	82.6	84.0
6	71.2	85.2	88.5
7	71.4	86.1	91.6
8	71.5	86.4	93.6
9	71.5	86.4	94.7
10	71.5	86.4	95.3

Figure 8. Effectiveness of FATE Points in an Even Fight

As expected, spending FATE points to increase attack or defense rolls increases the likelihood of winning combats. Having more FATE points to spend increases the benefit. However, at a certain point the increase levels off as the character has more FATE points than they will be spending for the fight.

Overall, spending points on both attack and defense rolls as applicable gave the best result. However, the defense results have some interesting quirks. The effectiveness of defense only spending falls off quite dramatically. This is likely the result of how the model was constructed. FATE points were only spent to increase defense rolls of -2 or lower, approximately a 1 in 5 chance on any roll. Even in fights with high numbers of FATE points available the vast majority lasted fewer than 18 rounds. 18 rounds would require 18 defensive rolls, on average fewer than 4 rolls of -2 or lower. This would explain the very minimal gains in having more than 4 FATE points.

However, the only time the mixed attack and defense expenditures were exceeded was for pure defense spending with only 1 FATE point, all be it not by much, 0.7%. My best guess is that it comes from rerolling really poor defense rolls. Rolls of -4 or -3 are reasonably rare at about 1 in 17. Thus it is unlikely that two such rolls would happen in any combat but one very well might. If the worst thing that could happen in a fight was a terrible defense roll then saving and using the character’s 1 point for that roll might be the best use of a single point.

The number of available FATE points is going to vary dramatically with the exact rules set and the campaign’s style. It seems unlikely that more than 3 or 4 points would be spent on an even combat. Fortunately, those are the most effective points in terms of increased wins per point spent, a little less than 8% per point.

Once again the article has gone on far too long. The next will cover the results of FATE points for uneven fights.

Writing For Games: Creating Your Own Scenario

Would you like to learn about how to write (computer) game scenarios?  Check out this meeting of the Society for Technical Communication (STC) – Puget Sound.  Some of the information may be transferable to tabletop.

Writing For Games: Creating Your Own Scenario

Date: October 18

Game scenario writing is more than a game; it can also be a great career. The next STC Puget Sound meeting will help turn your interest in gaming into a career writing game scenarios. Local game scenario writers Mark Schuldt, John Sutherland and Hal Milton will explain how to create narratives, game mechanics and scenarios. They will also discuss how to make the mental switch from technical writing to game writing and the state of the video game industry.
To register, http://stcoct2011.eventbrite.com/

Coming to terms with FATE

This series has taken a number of looks at the FATE system in various of its incarnations. One thing that I have diligently avoided is looking at the use of FATE points in combat results. The reason for this is the difficulty of the FATE point rules. They offer a number of choices for a limited resource and their use is situationally driven. However, they represent a very important part of the FATE system and a full understanding of the system requires taking a look at FATE points. In order to bite the bullet and take a look at how FATE points change combat, I first needed a model of FATE combat. Previous articles have looked at Spirit of the Century and FATE 2.0 but I’m not really a fan of those particular versions of FATE. I prefer the overall layout of combat in Starblazer Adventures or the Dresden Files.

This article describes building and testing a Monte Carlo model of an entire fight between two combatants, not just a single roll of the dice, using the Dresden Files FATE combat system. I have used these types of models frequently and the goal here is to take a detailed look at what I’m doing when I put one of these models together. Those uninterested in the model and wanting to cut to the chase should just skip to Table 1. Once I have a functioning basic model I then intend to incorporate FATE points. The actual results of incorporating FATE points will be in the next article.

Game Recap: The Knights of Midwestville Issue #2 Monster Mash

“What’s that commissioner? A giant monster is rampaging through the state. The governor has called out the National Guard but most of their equipment is still in the Middle East. You want the Knights of Midwestville to make sure no one gets hurt. We’re on our way commissioner.”

Sparky, teenage electrical controller, flew ahead riding on a cushion of lightning. Forcespike had used her disco themed invisibility ray to turn him invisible, though the lightning would probably give his position away. He was followed by Turbo Smash and Forcespike in the “Minivan of Justice” while Luminon flew above them on a column of light.

The source of the trouble soon became obvious, a 30 story tall, cone shaped monster with three tentacles ending in giant suction cups and three giant eyes evenly spaced around its body. Sliding along the fields it was suctioning up the corn harvest and crushing everything in its path. To the West Sparky could see the National Guard moving in. 

The Limits of Wealth: a boundary problem in Diaspora

Diaspora is a FATE based game aimed at creating a somewhat hard sci fi feel similar to Traveler, rather than a science fantasy setting like Star Wars or Star Trek. One of the qualities that it tries to emulate from Traveler is the economics of running a small merchant vessel. However, the economic mechanics of FATE do not mesh well with a business simulation and I feel that the resulting rules are simply terrible. What makes it interesting is that it is a different type of failure than the previous articles have discussed, a boundary problem.

Mechanics

Rolls in Diaspora use a typical FATE set up, roll four fudge dice, each numbering from -1 to 1, yielding a roll from -4 to +4 and adding a skill. If a target number or better is rolled, the roll succeeds with possible bonuses for how much the roll exceeds the target. If the roll is lower than the target, the roll fails and may result in penalties for how much the roll is short of the target.

Game Convention Blurbs

On his blog, Ryan Macklin — game writer, podcaster, and producer — has some very good thoughts about how to write a good game “blurb”  for advertising at a convention and, I would add, for weekly games too.

I’m not going to repeat his ideas here, I’d rather you read it from him, but I also want to point quickly to some thoughts I jotted down here some time ago on running a con game, including writing game blurbs.

Having recently prepared the convention for Dragonflight for the fourth year in a row, I can tell you that most GMs don’t put enough effort into their game pitch.  It’s often unclear, too long and verbose, or merely grabbed from an online review (like those from RPG Geek and Board Game Geek).  When you scroll through the list of games, it doesn’t make your eye and brain stop on the description.

Despite what Ryan describes, I get most of my convention players from people who liked the game description friends, of course.)  I always make sure my game blurb doesn’t look like “second verse, same as the first!”

Teaming in PDQ

Over the course of several products Atomic Sock Monkey has generated many variations on its basic PDQ mechanic. One set of mechanics that has received multiple treatments are the rules for teamwork.

Mechanics

For non-conflict rolls in PDQ players roll 2d6 and add the result to the character’s skill, which will be divisible by 2 i.e. 0, +2, +4 etc. If the total equal or exceeds the target number set by the game master the roll succeeds. Conflicts are slightly more complicated. In The Zantabulous Zorcerer of Zo and Truth and Justice rolls in conflicts are basically the same as normal but instead of rolling against a target number the attacker rolls 2d6 and adds their attack skill while the defender rolls 2d6 and adds their defensive skill. For every point that the attacker’s total is higher than the defenders the defender takes a point of damage. In Swashbucklers of the 7 Skies players get to divide 3 dice between attack and defense rolls, so an attack will be 0 to 3 d6 plus the attacker’s skill against 0 to 3 d6 plus the defender’s skill. The point of this article is to compare the teamwork rules, not the huge change in the basic combat mechanic. So for this article it will be assumed that all rolls are made on 2d6.

What Makes a Good Combat Option

Many games offer optional actions in combat that differ from a standard attack, like throwing sand in someone’s eyes to temporarily blind them. These options can allow a player to accomplish things that they couldn’t do with an ordinary attack or give them choices to make combat more interesting than just saying “I attack them” again and again. As I’ve addressed in columns about specific mechanics, the problem is that many game designers just don’t seem to get what it takes to make a decent combat option. This is a summation of my rants about what a combat option should be like.

Some PDQ Thoughts on Combat

I’ve been playing around with a DnD like port for PDQ. In doing so I started thinking about something like ‘GM tips’ on setting up combats using PDQ. Here are some of my ideas on setting the defensive skills of the opposition and how much damage they should be able to take.

Mechanics

In order to damage an opponent in combat a character rolls 2d6 and adds their attack ability, which will be divisible by 2 so 0, 2, 4, etc. The defender rolls 2d6 and adds their defensive ability, also done by 2’s. If the attacker’s total exceeds the defender’s the defender takes one point of damage for every point that it is higher. So if the attacker rolls a 10 and the defender a 7, the defender takes 3 damage. The damage comes off of a character’s abilities. Once a character runs out of abilities to damage they are defeated.

One wrinkle is that there are several editions of the rules. In some if there is a tie then both characters take a point of damage and they roll again until one has a better roll than the other. This analysis will be slightly off for anyone using that rule. Some editions have attackers take damage for every point that they miss by. So if the attacker rolled a 7 and the defender a 10, the attacker wouldn’t just miss, they would take 3 damage. In PDQ sharp characters get 3 dice for combat and can use 0 – 3 of them for their attack and the rest for defense. Either of these rules significantly alter combat and this analysis just can’t apply to games using one of those rules.

NEW GAMES ADDED

Wade Rockett will be running an octaNe game from 10:00 am – 2:00 pm.  Here’s the description -

Seattle’s Chinatown has been sealed off from the rest of the world by a mysterious force – with you in it! Face off against Triad gangsters, sexy ghosts, hopping vampires, ancient demons and more as you struggle to find a way home. Pregenerated characters will include a wide variety of people who might be in the ID on the 4th of July weekend, such as a cosplaying anime fan, a Hong Kong detective on the trail of a crime boss, a member of the local fighting tong, a Taoist sorcerer, or Ichiro Suzuki. Spend power points to receive lucky red envelopes containing facts and rumors, surprising secrets about your character, or new twists to the story! octaNe is a rules-light game for those who love improvisational roleplaying.

We’re still looking for more games.  Come on – you know you want to run something!  Drop me a line at tlucretius@gmail.com and sign up to run something.  Help support the game community in Seattle!