This article is the sixth in a twelve part series that talks about the choices/decisions that need to be made when designing a role-playing game system. This time I talk about mechanics for position, distance, range, and movement.
Q: What kind of position tracking system do you want in your game?
The options for position tracking systems are a lot more nuanced that “abstract vs. tactical”? In fact I would use 3 axes to describe position tracking systems:
Abstract vs. concrete: here “concrete” means distance is measured in real world units or units that are easily converted into real world units (e.g. 5 foot or 1.5 meter squares); whereas “abstract” is less literal.
Informal vs. formal: this is the level of detail in the rules concerning position. “Informal” means there are little to no rules covering positioning, whereas, formal indicates a more detailed approach.
Relative vs. tactical: “tactical” means position is tracked using miniatures on a battle map of “1 inch” (or other size) squares or hexagons where distance and position matter. “Relative” is looser. The GM will say something like “the orc is about 15 feet in front of you and a little to the left; the troll is about 25 away from you, to your front and right” or “the Barabel is on the cat walk above you.”
So how do these three axes combine in published games?
AD&D’s position tracking system was concrete, informal, and relative. Distance was measured in feet or yards which makes it concrete. There weren’t really rules for tracking position, which makes it informal. And the GM described relative positions between characters, of course sometimes a GM might sketch a map on a sheet of scrap paper and say “you’re here, he’s there,” but these weren’t “battle maps” with 1 inch squares or hexagons on it so the system was relative rather than tactical.
D&D 3e introduced the concept of 5 foot squares (so it was concrete), but it didn’t go all in on them so it was kind of transitional between relative and tactical. “Flanking” an opponent provided a bonus to hit and enabled special abilities like “sneak attack” so its positioning system was at least formal. D&D 3.5’s positioning system was definitively tactical, formal, and concrete; heck diagonal squares counted as 1.5 squares. D&D 4e’s positioning system is also tactical, formal, and concrete but it de-emphasized the conversion from squares to feet, and while it may not seem like much to those who haven’t played tactical RPGs its counting of diagonal squares as 1 square was a major step forward.
The positioning system in Star Wars Saga Edition (a d20 system by Wizards of the Coast) was tactical, and formal; in character scale combat it was concrete (1.5 meter squares) but in vehicle (e.g. starship) combat the size of squares is abstract.
The position tracking system in Edge of the Empire (and Age of Rebellion, and presumably Force and Destiny) is relative, formal, and abstract (it is insightful to contrast this against AD&D’s relative, informal and concrete system, both of which use the “theater of the mind”/relative approach but share little else in common). It’s abstract because distances are measured in range bands that are not readily convertible to real world units. It’s formal because positioning is explicitly covered in the rules (for example you need to spend a maneuver to get into cover, even if you’re next to an object that could provide cover).
Marvel Heroic Roleplaying uses a position tracking system that is abstract, informal, and relative. It almost doesn’t have a position tracking system. All of the characteristics relevant to a hero are found on their data file, and almost all of them are abstract and traits that are specific to the hero in question. For example, Spider-man has a wall crawling trait but the majority of heroes don’t have a movement trait. The bad guys get away if the “Watcher” (GM) spends two twelve sided dice from the doom pool to end the scene/encounter. It’s generally assumed that any hero can attack any villain in the scene on their turn.
Pros and Cons: For narrative purposes you want there to be between 3 and 6 rounds per minute. That is combat encounters should last at least a minute of simulated time and 2 minutes is better. You also want most combat encounters to last between 5 and 10 rounds so players won’t get bored. Your “narratively optimal” choices for a round with fixed duration are: 10 seconds (6 rounds per minute), 12 seconds (5 rounds per minute), 15 seconds (4 rounds per minute), and 20 seconds (3 rounds per minute). However, the “mechanically optimal” duration of a round for a tactical position tracking system is 6 seconds. This is a primary drawback of a tactical position tracking system.
You may be wondering where that 6 second figure comes from. A character’s base speed needs to be small enough that tactical movement will fit on a battle map of 1 inch squares. Characters shouldn’t be able to move more than 12 squares in a round without running.
You may be thinking “But in D&D 4e and Star Wars Saga Edition, characters have a base speed of 6 squares, doesn’t than mean 10 second and 12 second rounds are allowable?” Not if you allow characters to spend their standard action to move a second time in a round. The optimal square size is “ABOUT” 5 feet or 1.5 meters. Five feet/1.5 meters is also a good width for a “narrow” (single square wide) hallway. Combining that with realistic movement rates narrows your choices for the duration of a round to either 5 seconds (12 rounds per minute) or 6 seconds (10 rounds per minute); 10 second rounds can be shoehorned in but it won’t be a good fit. Six second rounds are chosen over 5 second rounds because 10 rounds per minute is cleaner and it also makes combat last longer from a narrative perspective.
Published RPGs (that I’m aware of) that simulate tactical combat well use a tactical position tracking system; it’s a thoroughly tested and proven technique that works. However, combat encounters can still be very fun in RPGs with non-tactical combat systems.
Published RPGs with tactical position tracking systems also have a particular flaw in common. Namely, attacks with ranges bigger than any battle map that will fit on a table. The typical approach to handling this problem is to default to a concrete, formal, relative position tracking system for long range combat (similar to what was used in AD&D under all circumstances). Saga solved this problem for the special case of vehicle vs. vehicle (e.g. starship) combat by using large abstract squares (that made long weapon ranges fit on a battle map); but long range character vs. character or character vs. flying vehicle combat was an unsolved problem in Saga.
Q: Is it possible to make an RPG that is a first class tactical combat simulator without using a tactical position tracking system?
I’m an engineer by training so when, in the process of writing this article, I asked myself whether it was possible to create a tactics based combat system that has an abstract, formal, and relative position tracking system (similar to the one in FFG’s Edge of the Empire Star Wars RPG: i.e. engaged, short, medium, and long distances) I answered the question by devising one. It’s a little tangential to the topic article, so I put the outline of the system in another article entitled Extreme Makeover, d20-ish Edition.
The central idea is that you have to pay a cost to use a tactic, but we want every character to be able to use one “tactic” each round. To me that said, make tactics part of the time tracking/action system, so that every round each character get one action (dice roll), one movement (sort of like a maneuver in FFG’s Star Wars), one tactic, and one incidental. A tactic is typically a modifier to the action.
Q: So what are the options for determining distances and ranges?
In combat, how you measure distances depends on whether you’re using a relative or tactical position tracking system. For relative ones, you can measure distance in abstract or concrete terms; personally I prefer that relative position tracking systems use abstract units of distance. Although AD&D used concrete units of distances, its distance/movement system had a pseudo abstract quality to it; one unit of movement equated to 10 yards when outside and 10 feet when inside.
For tactical position tracking systems you’re typically going to need to decide how big a square (or hexagon) is in real world units (i.e. concrete units) so you can say how precisely far away from cover a character is. In open water, open skies, or outer space, your squares/hexagons can have abstract sizes. However, even when squares have a concrete size, you have the choice of either strongly or weakly linking square size to real world units. D&D uses 5 foot squares and Star Wars Saga Edition uses 1.5 meter squares. In D&D 4e that linking is tight because how far characters can jump is measured in feet whereas Saga uses “squares” for small distances. I followed Saga’s paradigm of using squares as the universal measure of short distances but my squares are “about” 5 feet or 1.5 meters, and gamers have the freedom to choose how to convert squares to real world units.
You also need to choose whether 1 diagonal square counts as:
- 1.5 squares (D&D 3.5 and Revised Core Rules Star Wars RPG);
- 2 squares (Saga reasoned that 1 square up and 1 square over equals 2 squares); or
- 1 square (D&D 4e)
Empirical evidence (game play by the masses) has led to consensus that the D&D 4e approach of 1 diagonal square = 1 square is the optimal solution; but it leads to the odd artifact of square fireballs.
We need to talk about representations of range (for ranged attacks) which can be different.
In Fantasy Flight Games’ Star Wars RPG the range and distance increments are the same; this tends to be true for any system that uses a relative position tracking system. But you need to decide whether:
- hitting any target within range is equally difficult (all you need to do is pick maximum ranges for a weapon);
- difficulty increases with increasing distance (most modern games follow this paradigm); or
- if, for certain weapons like a guided missile, it could be actually be easier to hit a target at longer distances than a short one (this is uncommon at best).
You also need to determine the ranges and/or range increments of individual weapons; choices include:
- varying the range from weapon to weapon;
- having the same range increments within categories of weapons (e.g. all pistols), but different range increments for different categories of weapons (e.g. pistols vs. rifles)
- having the same range increments for all weapons, but different weapons or different categories of weapons have reach targets at a different number of range increments.
Q: What are the options for movement systems?
After you’ve chosen the positioning tracking system and methods for determining distance and/or range, you still need to determine how far individual characters can move in a unit of time. In most games, this is either the same for everyone or it is determined solely based on the character’s race/species; often this base speed can be decreased depending on how much you’re carrying or what armor you’re wearing.
One innovation from the Palladium RPG system, the first place I saw it, is that speed was an attribute (like Physical Strength, I.Q., etc.) that could vary from one member of species to another. This feature is uncommon but it does occur in more modern games in a modified and limited form. In the Saga Edition Star Wars RPG, there are two talents in the scout class’ Fringer talent tree, “long stride” and “Run”, which respectively increased a character’s base speed and let them run at 5 times rather than 4 times their speed. This is a step up from having speed solely determined by race. I can see the motivation for having uniform base speeds in a tactical position tracking system (characters with higher speeds could have huge tactical advantage), but this makes resolving chases scenes difficult.
In a TV show or movie, chase scenes generally ends fairly quickly, with either the person being chased gaining a bit of a lead and then rounding a corner and disappearing into a crowd or getting tackled by the person chasing them. In RPGs where “everyone” has an identical speed the gap between them never closes and never widens, and that gets boring. The typical approach is to break the stalemate by using endurance checks to force one of them to stop running, and that’s anti-climatic. Narratively, ending a chase scene with a tackle is a lot more satisfying.
If characters are able to fly that brings in another set of challenges, since they can generally fly much faster than they can run. This also makes fitting a combat encounter on a battle map difficult and will generally add the extra complication of having two different speeds for a character. The same applies to swimming, climbing, and jumping.
Q: What did you do for position tracking, distance, and movement in your 3D RPG?
For tactical combat I use a concrete, formal, tactical positioning tracking system with uniform base speeds but non-uniform running speeds. For chase/race scenes I use a concrete, formal, relative position tracking system, and the transition between the tactical and relative position tracking systems is seamless. Non-uniform running speeds allow for chase scenes to be resolved with a narratively satisfying tackle or escape, and since the non-uniform part of running speeds depends on dice rolls the outcome is not a foregone conclusion at the beginning of the chase.
Characters do not have to spend all their squares of movement for a round at once. As long as they have squares of movement left for the round, they can move as many times as they like during their turn, and up to once per each other character’s turn. When multiple characters want to move at the same time, whoever’s turn it is decides the order in which characters move. This avoids the need for “readied actions” to move.
Readied actions are a complicated patch needed by a suboptimal time tracking system (fixed initiative order). It’s better to choose a time tracking system that doesn’t need to be patched in the first place. You can read about the time tracking system I chose for my 3D RPG in part 3 of this series. Generally, if anything seems too complicated to you, the designer, it probably needs work.
Whether in a tactical position tracking combat encounter or in a relative position tracking chase/race scene, distance is always measured in squares where a diagonal square counts as 1 square and the coupling of square size to real world units is loose rather than tight. There are 2 sizes of squares: normal squares (sq.) and flying squares (SQ. which is in “big” or capital letters because SQ. are much bigger than sq.). A normal square is about 5 feet or 1.5 meters. In atmosphere, one flying square is EXACTLY 50 normal squares long and there are EXACTLY 21 flying squares in either 1 mile or 1.6 kilometers (English or Metric, as the group decides).
When tactical position tracking involves flying characters, each 1 inch square on a battle map represents 1 flying square, which allows extremely large distances to fit on a battle map that fits on a table. To make the transition from ground to air seamless, a flight capable character’s base (tactical) speed on the ground when measured in sq. equals their flying base speed when measured in SQ. (unless hovering slowly to engage characters on the ground, then flying base speed in sq. is 10 times their land base speed).
In space, flying squares grow to a much larger and abstract size, but a flying character’s movement rate as measured in units of SQ. does not change when they leave the atmosphere. Weapon ranges get the same boost. This makes transitioning between endo and exo atmospheric flying combat happen seamlessly.
The ranges of weapons are listed both in sq. and SQ. There are 4 range increments: short, medium, long, and extreme. The number of squares in a range increment are constant within each category of weapon (e.g. thrown, pistol/bows, rifles, heavy weapons); but they differ from category to category. I’ll talk about this in more detail next time, i.e. in part 7 of this series, but weapons have a die for “damage” and a die for “finesse,” either or both of which can be included in a dice pool for attacks made with that weapon. Ranged weapons can have a different finesse rating/die-size for each range increment. This allows a guided missile to actually become more accurate as the distance between the target and the shooter increases; while rifles increase in accuracy going from short range to medium range and then decrease with further in increases in range; and pistols are the ultimate short range weapons. It’s a lot more realistic than fixed penalties for range increments while still being fairly simple.
When I started writing this article, there was something about my movement system that I didn’t like. A character’s run speed (for a single round) in squares was their speed multiplier times the first die of their dice pool plus their base speed (which was typically 12 sq.). And a character’s running speed multiplier was 2 plus the larger of their Brawn and Dexterity multipliers or 10, whichever is less (Brawn and Dexterity multipliers greater than 1 reflect super human physical attributes).
World class athletes (having running dice pool of 3d12) would be able to run the 100 meter dash in times close to the world record when using the destiny mechanic (read about my destiny mechanic here). The formula for running in 30 second time increments was slightly more complex to give realistic times for world class athletes running 400 meters. What I disliked about it is that for fast and smooth play, gamers should never have to multiply by anything other than 2, 5, 10, 20, 25, 50, or 100; multiplying by 3 is marginally acceptable, but I still felt my old running speed rules were too complex.
Here’s what I’ve come up with. Most characters’ base speed for a 6 second round is 10 squares. When running for one round, their running speed equals a number of sq. equal to their base speed times their speed multiplier plus their normal base speed plus the sum of the first and second dice in their pool. For most characters, this is
10 x speed multiplier + 10 + first die + second die.
So the math is now really simple. Also their running speed multiplier is now the larger of their Brawn and Dexterity multipliers (capped at 10), so for most characters the speed multiplier is 1. This new rule gives world class athletes using destiny realistic times for both the 100 meters and 400 meters, it also gives “normal” people realistic times for running 100 meters. When I was 18-20, I ran on the cross country and track teams at a community college. Using destiny, the numbers say that my average time would have been 11.87 seconds and a very-doable-on-a-good-day speed was 11.58 seconds, and my best possible speed would have been 10.94, which covers the 4 by 100m relay time. Since these are close to my actual times it’s realistic for normal people, too.
To give people a better idea of what the sizes of dice mean, Usain Bolt (the world’s fastest man) would probably have a running dice pool of 2d12 & d10 where the d10 comes from either Brawn or Resilience.
When running for 30 seconds (5 rounds), your running speed is half your base speed times your speed multiplier plus your normal base speed plus your first die plus your second dice and multiply all of that by 5 rounds. For most characters this is
(5 x speed multiplier + 10 + first die + second die) x 5.
So now the math is very simple; you only have to multiply by 5. This rule also gives world class athletes using destiny realistic times for 400 meters. And using destiny, the numbers say that my average time would have been 55.93 seconds. My best was 56 seconds, but I could do 56 seconds whether I gave it everything I had (and “ran out of gas” and had to slow down before crossing the finish line) or I was slacking (and didn’t need to slow down), so I’ll call 56 seconds my average time too. So again, the new rules also give realistic times for normal people.
So why do I have rules for running in 30 second increments? The primary reason is to reduce the number of dice rolls that are needed to resolve race/chase scenes and to cover larger distances. At any point in a combat encounter, a character can declare that they want to flee and other characters can declare that they want to chase them; this pulls them out of normal time tracking and into a race/chase scene. They each start with some number of squares in their distance totals. Every 30 seconds, the characters make one run check (for 30 second time increments) and add it to their distance total.
In a chase scene, the fleeing character escapes if his/her distance total ever gets to be 100 sq. or more greater than all of the chasing characters; and a chasing character catches the fleeing character if the chasing character’s distance total ever equals or exceeds the chasing characters. To tackle the fleeing character, the chasing character has to catch the fleeing character when taking a double action consisting of running and grappling (i.e. Brawling has to be included in the dice pool). There is roughly a 28% chance an equally matched chase scene will end in 1 roll, 50% chance that it will end within 3 rolls, and 70% chance that it will end within 6 rolls.
Race scenes are a lot like chase scenes. The race ends when one or more characters’ distance total exceeds the finish line distance. If multiple characters reach the finish line with the same roll, then the order they get there is in decreasing order of their distance totals. If, when the race starts, the closest person is less than 100 sq. (2 SQ.) from the finish line, rounds are the units of time used for the race scene; in this case, each person adds their 1 round running speed to their distance total for each dice roll. Otherwise, 30 second time increments are used for the race.
Characters can “walk” leisurely at a speed of 1 SQ. per minute, “jog” at speed of 1 SQ. per 30 seconds, or “run” at a rate of 1 SQ. per 2 rounds (super human characters may be able to run faster). If you “walk” or “jog” you still get to roll a dice pool each round; to “run” using this rule, you sacrifice your dice rolls for as long as you are running, and you can keep up that pace without rolling for a number of SQ. equal to the size of the largest die in your running dice pool times your speed multiplier. Alternatively, you can make a run check to determine how many SQ. can move in 5 minutes. The formula is
5 x your speed multiplier + 5 + your first and second dice.
For most characters this is 10 + your first die + your second die, and it gives reasonable times for 1 mile (21 SQ.) and 2 miles (42 SQ.). In terms of what the numbers mean, “running” for 5 minutes equals “jogging” for 5 minutes plus the sum of your first and second dice in SQ.
So what dice can be included in a running dice pool? Brawn and Dexterity are the attributes that are typically relevant for running. Athletics is the required skill for running (and climbing, swimming, and jumping). If obstacles are involved, acrobatics is relevant. If you want to pole vault a fence or wall, then “weapon proficiency: staffs, spears, and polearms” is relevant. Other special circumstances bring other relevant skills to bear. And if you can think of a narrative reason for any other skill or attribute to be relevant, it is (subject to GM approval but GMs should generally approve of anything that makes for a good narrative).
Q: What about difficult terrain?
If you’re only moving your base speed, then each square of difficult terrain still counts as one square. If you’re running, then each square of difficult terrain counts as 2 squares, UNLESS you include acrobatics in your dice pool, in which case each square of difficult terrain still counts as 1 sq. This would be parkour style movement which is sometimes also called “free-running.”
Q: What did you do for climbing and swimming?
- For 5 rounds (30 seconds): Your first die is how many sq you climb in 30 seconds.
- For 30 rounds (3 minutes): Multiply your first die by 5; that’s how many sq you climb in 3 minutes.
- For 30 minutes (300 rounds): multiply the sum of all three dice by 20. That’s how many sq you climb in 30 minutes.
The preceding numbers are slightly optimistic for world class athletes (Dan Osman managed about 400 feet/120 meters/80 sq in 4 minutes 25 seconds). Automatic failure results in no progress being made for the time increment. Critical failure means you must succeed at a saving throw or fall.
For swimming, the number of sq. that you can swim in a round equals your Brawn multiplier times your first die. This formula beats world records by a significant margin but isn’t terribly unrealistic, and the alternative is to divide your first die by 2 and add a base speed; that would be more realistic but also more complicated, so I chose the simpler solution. For tactical movement (battle map) swimming at SQ. scale, characters can swim 1 SQ. every 30 seconds and can swim a number of SQ. at this pace equal to their Brawn multiplier times the size of the largest die in their swimming dice pool. Alternatively they can swim 1 SQ. per minute indefinitely (but GMs’ are discouraged from letting them swim for more than 3 days without resting); again, that isn’t perfectly realistic but RPGs are about larger than life heroes and the rules need to be simple.
Q: What did you do for falling?
My rules for falling are based on physics, and I still managed to keep them fairly simple. Long time listeners of the Order 66 podcast, might recognize these as being a modified version of the ones that appeared in episode 115 “Vong but not forgotten” of the Saga edition era Order 66 podcast.
When falling from great heights characters fall 100 sq (2 SQ) the first round, 200 sq (4 SQ) the second round, and 220 sq (5 SQ) every round starting with the third. Characters also have a glide speed of 10 sq per round that they can use to reduce or increase their fall speed or for horizontal movement. If distances are measured in SQ., then characters can choose to reduce their terminal velocity (third round and later) from 5 SQ. to 4 SQ.
The damage a character takes from a fall depends on their initial height; it is always 3 of the same type of dice. The cut offs are chosen to be memorable and realistic: 0 damage for falls less than 3 sq.; 3d4 damage for falls between 3 and 15 sq.; 3d6 for falls between 15 and 35 sq.; 3d8 for falls between 35 and 75 sq.; 3d10 for falls between 75 and 175 sq.; 3d12 for falls greater than 175 sq. These damages corresponds to speeds of 15 m/s, 25 m/s, 35 m/s, 45 m/s, and 55 m/s (so damage scales linearly with speed) and the distance cut offs are accurate to within about 5 m/s (assuming gravity and an atmosphere are similar to earth’s).
Play Testers Wanted
This is the sixth article in this series, so by now you’ve seen that the rules in my 3D RPG streamline game play and are narratively satisfying, simple, well balanced, and realistic (at least more realistic than any other RPG that I know of). Basically, my goal was to design a RPG that does all things well and I think I’ve succeeded (there are more narrative games and more tactical games, but I think I hit the sweet spot between them). I haven’t fully detailed how tactical combat works yet (I’ll cover that in the next two installments), but given what I’ve told you about my system so far I’m hopeful that you’ll trust me when I say that it works very well and runs fast and smooth. And if you don’t trust me then I hope that you’ll take GM Dave’s word that my 3D RPG is a pretty slick system (you can listen for yourself in episode 14 and post show of episode 3 of the Order 66 podcast, Fantasy Flight Games reboot). So if my system sounds cool or at least interesting to you, then I encourage you to send a PM to EliasWindrider over on the d20radio.com forums to sign up as a play-tester. I’m also about to start an online campaign using roll20 if you’d like to playtest it that way.
Gamer Nation Studios is the game design company that will be publishing my 3D RPG. The first book is going to feature a slightly stripped down version (e.g. no cybernetics/robots chapter) of my system for a traditional (D&D style) fantasy setting. If you have the time, inclination, and talent to be a world builder then send a PM to EliasWindrider on the d20radio.com forums.
You can read more about the setting here.
If you’d prefer to publish a separate setting book using my system that’s OK too and I don’t need to be involved in it; my system is going to be released under the Open Gaming License.
This work, unless otherwise expressly stated, is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.