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MixingYourMetagamingMetaphorsWritten 27 July 1996 by George F. Rice
One of my children’s favorite crafts is to halffill an empty 2liter soft drink bottle with water, add blue food coloring, and fill to the brim with cooking oil. The oil and water do not mix, of course, and by rocking the bottle they see a reasonable facsimile of ocean waves at the beach. One of their favorite games, on the other hand, is The Fantasy Trip (abbreviated TFT). They inherit their bias from me, for I have found TFT rules to be highly logical, easy to apply, balanced, and more fun to play than competing systems. My store of programmed solitaire adventures, which can be played with the unmodified rules, makes the TFT gaming system even more popular in my household. Convincing seasoned gaming friends to play used to be a problem, however, due to a quirk in the TFT rules: All die rolls use standard 6sided die. Their impressive collection of 4, 8, 12, and 20sided die simply weren’t needed for the worlds I created, resulting in a marked lessening of enthusiasm. But are polyhedral dice and TFT rules like oil and water, destined to forever live separate virtual lives? In a word, no. This article attempts to establish a rationale for using polyhedral dice within the TFT rules. In defining these rules, my goals were:
Making a Game PlanTo avoid affecting the balance of the game, the player using polyhedral dice must make the same average roll as the player using traditional dice. A player who rolls a die many times will, on average, roll the sum of the largest and smallest possible value divided by two. So, the average roll on a 6sided die is (6+1)/2 = 3½; for a twentysided die, the average roll is (20+1)/2 = 10½. The average roll for multiple die is the sum of the averages of each individual die. So, the average damage for a broadsword, 2 6sided die (abbreviated 2d6), is 3½ + 3½ = 7. If we rolled 2 8sided die for broadsword damage, we would have 4½ + 4½ = 9 — too much by two. But if we subtract 2 from each damage roll, the average roll will be (4½ + 4½)  2 = 7. In terms of game balance, then, it doesn’t matter if you roll 2 6sided die for broadsword damage, or 2 8sided die and subtract 2. You will average 7 points of damage per hit in the long run. Yet the effect is not precisely the same. The maximum damage using 2d82 is 8 + 8  2 = 14. Using 2d6 the maximum damage is only 6 + 6 = 12. Similarly, minimum damage using 2d6 is 2, but with 2d82 is 0. This, then, is the improvement afforded by polyhedral dice. Individual broadswords may do 2d6 of damage, or 2d82, or even 2d4+2. Each weapon affords the same average potential for inflicting damage. But one weapon is more consistent (2d4+2), causing from 4 to 10 points damage per hit, while another varies much more widely (2d82), causing from 0 to 14 points damage per hit. Weapons take on more character, and battles become more interesting. Defining the BoundariesThe newandimproved TFT rules, then, are as follows.
Appendix A presents a table of weapon profiles. To determine the available profiles for a given weapon, find the TFTdefined damage on the table. All other profiles in its group are possible, and may be available at your local weapons shop. Avoiding the PitfallsA damage profile like 1d4 2, where the subtracted adjustment is larger than the number of die rolled, does not have the expected average value of (1+4)/2 2 = ½. Since nonmagical weapons cannot do negative damage (that is, increase the target’s strength), the actual average damage is (0 + 0 + 1 + 2)/4 = ¾, slightly higher! For simplicity, then, such damage profiles are not allowed in the new rules. Launching the AttackNot only does the range of possible values change with polyhedral dice, but also the statistical distribution (that is, your chances of rolling less than a given number). This change in distribution doesn’t matter when you are rolling damage, but it does matter if you are making an attack or saving roll. The average roll for attack dice (3d6) is 10½, coincidentally the same as the 1d20 attack die popular with some other systems. However, your chances of rolling an 8 or less with 3d6 is about 26%, while your chances with a 1d20 is exactly 40% — a much better chance. If we plot statistical distribution for the two attack systems, we see that rolls below 10 are easier with a 1d20, while rolls above 10 are more difficult (the 1d20 distribution is the straight line). While we could map each adjusted dexterity 3d6 to an equivalent 1d20 roll (for example, to hit with AdjDx = 8, you must roll 5 or less on 1d20), this solution is messy and unpalatable. If we are to consult a table for each attack, we may as well use one of those other gaming systems! A simpler solution is to decree that either all players use 3d6, or all players use 1d20. If 1d20 is chosen, then the following rules should replace the “5 is automatic hit, 4 is double damage, 3 is triple damage” provisions of TFT.
These two rules replicate almost exactly the results of the existing TFT “extreme roll” rules. If you like the critical hit rules of TFT, try this table with a second 1d20 each time an attack roll result is 1 or 2.
More interesting still would be a table for exceptional success (1) or exceptional failure (20), giving a different result for each value rolled on a second 1d20. These two tables are left as an exercise for the reader, since they will be more interesting if they take into account the surrounding milieu. Note that using a 1d20 for an attack die will change the character of the game somewhat, since it will be easier to hit with low AdjDx but harder to hit with high AdjDx. Experience has shown that this is not a significant change, especially if your friends are stuck on the belief that a 20sided die is an attack die by definition. Saving rolls using more than 3 6sided die should be performed using 6sided die; they are not “attack rolls” after all. When planning traps, your labyrinths can take advantage of the newfound flexibility in defining detect and disarm rolls. For example, a particular trap may require 5d8 vs. IQ to detect and 3d12 to disarm. Not only does this give you more control of the chances of success for particularly smart or dexterous characters, it also allows flexibility in the advantage afforded the character with Detect and Remove Traps talents (rolling 2 fewer 12sided dice makes the trap much easier for a knowledgeable thief than usual!). Sweet SuccessMixing oil and water may seem a strange recipe for success, until you see the excitement as the waves roll into the bottlecapped shore. Mixing polyhedral dice into the Fantasy Trip system can likewise increase your enjoyment of the game by providing more variety, flexibility, and options to your little corner of Cidri. Appendix A: Weapon Profile Table
 
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Page last modified on July 10, 2018, at 10:49 AM 