Combat In Motion is a new 3rd party supplement for Dungeons and Dragons 4E. You can learn more about it (or order a copy) from the Enhanced 4E website. It's essentially a set of house rules that aim to provide more tactical depth to an already tactically-rich game. Most of these new rules are fairly intuitive, resulting in an increase in simulationism, a more accurate representation of the game-world, or an increase in cinematic structure. One might call many of these new rules "patches" for the weak spots in the core 4E rules, sometimes adding layers to the existing mechanics and other times replacing them outright.
As might be expected, the new rules are largely modular so that individual GMs can pick and choose what they want to use. After all, some of the new rules offer more complexity for the increased realism and not all GMs will want that much more complexity in their game. I have a feeling that few people will prefer to adopt every single new rule for their game, but few people would also pass up on every single new rule; after giving the book a read-through, most GMs (or players) would likely occupy a middle-ground, wanting to incorporate some but not all of the new material.
One of the highlights of this book is that whereas specific tactics utilized would often depend on your choice of class in core 4E, all of these new rules are universal. The one caveat is that characters without a strong basic attack are penalized by making some of the more attractive options virtually non-existent, so I would highly recommend giving out Melee Training for free, and possibly creating a similar house-rule that opens more classes up to Ranged Basic Attacks as well. By using this book you're already houseruling: you might as well ensure that you're being egalitarian about it.
As a final note I'd like to point out that while these new rules were designed to work with D&D 4E, and like the base system rely heavily on a battle grid, many of the new concepts can be applicable to other systems (even those employing a theater-of-the-mind combat style). Indeed, there are a few concepts that I found myself eagerly trying to mentally squeeze into the rules for drastically different systems, and it wouldn't be too much of a stretch to tweak your favorites to apply to your system of choice. Some of the new concepts are different from anything I've yet seen in tabletop RPGs, which is pretty exciting!
The New Battle Grid
This chapter is obviously dependent on grid-based play, and is arguably the most "independent" of the new concepts that the book introduces. What this chapter does is make the representation of the game world on a battle grid more closely resemble 3rd Edition than 4th Edition D&D. Instead of square fireballs and diagonal movement being equivalent to horizontal movement, these new rules seek to make the grid geometry fit more mathematically smoothly with the imagined world.
Unlike 3rd Edition D&D, which accomplishes this in purely numerical terminology, the Enhanced 4E system references the in-world metric of "paces." While this is pretty easy to wrap your head around, it does require some mental conversion, especially since it will sometimes be more convenient to measure things in-game using squares, and other times using paces. How it works is that there's a square-to-paces conversion, with movement across a square's diagonal costing more paces than horizontal movement. Likewise, even if a burst or blast still technically takes up a square area, a creature must still be specifically within range of the origin in paces. A creature within the square area but standing in one of the corners is thus not affected.
Personally, the spatial distortion of standard 4E never bothered me much. After all, we're all used to the phenomenon in real life even if we aren't aware of it -- a map is a two-dimensional representation of a three-dimensional object (the earth). All maps display distortion of some kind, with different map projections minimizing distortion of some variables while sacrificing others (variables include distance, area, shape, and direction). Think of a world map; the land near the poles appears proportionately larger than the land near the equator than it actually is (compare it to a globe to see for yourself). Anyways, if you think about standard 4E's simplified grid in the same way it seems a lot more tolerable. The tradeoff, of course, is for ease and speed of use. A square is a lot easier to mentally project onto a grid than a more complicated shape like 3E's area effect templates, and likewise counting squares is more quickly resolved than keeping track of how many diagonals you trace on your path and remembering to subtract additional paces.
Personally, this isn't a chapter I would use because the distortions of standard 4E's simplified measurements don't bother me, and their effect on the speed of play is something that I find extremely valuable. That said, for those who prefer the 3rd Edition system and/or those whose sense of immersion is strained by 4E's more simplified approach, this chapter is as good a solution as any. Indeed, the in-world "paces" terminology might be more intuitive than the default 3rd Edition system for some; at the very least there are now 3 options to choose from. Ultimately, this chapter caters to more simulationist gamers, but that's definitely not a bad thing. 4E already provides the default option for the gamists, and providing an alternative for those who prefer it can only be classified as a good thing.
I personally find the concepts of this chapter to be a little jarring, but I haven't playtested anything in this book, so for all I know they work more fluidly in-play. Of course the reason why this chapter exists is because the authors found the stop-start movement of the default turn-based paradigm to be jarring, so your mileage may vary. In a nutshell, the new rules presented here provide the option for creatures to end standard and move actions in which they moved either "in-motion" or "motionless." In other words, over the course of multiple turns is the character whacking an enemy with his sword as he runs past, or is he running up, taking a few swings while standing toe-to-toe, and then running away?
The key here is that when in-motion, actions taken by a character will be mechanically influenced by actions previously taken. Some of the new action types presented later will trigger off of motion state, and creatures in-motion gain facing properties (spatially-based bonuses and penalties) and a "trail" (which influences facing, as well as where you can move later). Facing squares are an attempt to model the fact that you can't focus your attention on certain areas around you as you're zipping by, and creatively uses the existing rules for concealment and combat advantage for simplicity's sake. You can also take advantage of your momentum in new ways; you don't provoke OAs for moving into your forward-facing space, you gain a movement bonus, and you can move into your forward-facing square at no cost to make a melee basic attack as a standard action.
Like many of the new rules in this book, what makes motion states interesting is that they're not always the exact right answer. In standard 4E, for example, it was always a good idea to charge if possible (and especially if you had the "charge package" of feat, item, and power-based buffs to charging). Because there are no drawbacks, there's really no tactical choice; if you can do it, you should do it. Your choices really came into play during character-building, which is less interesting. Being in-motion can give you an advantage over some enemies, but cause you to be vulnerable to others. And this isn't just because of the flat bonuses and penalties it provides; it may also trigger off-turn actions for both your allies and enemies, to your advantage or inconvenience.
I've heard the argument many times; the abundance of opportunity actions and immediate actions in 4E bogs down combat. Does that mean that the addition of a new type of off-turn action will bog down combat even more? Again, I've not playtested this yet, but I'm going to have to go with "not necessarily." The key to this is the concept of actions "borrowed" from future turns, tracked by the new "sapped" and "tapped" conditions. Sapped means you've already used your move action off-turn, and Tapped means you've already used your standard action (they are therefore not available when your real turn comes up). Effectively you're not gaining any more actions, but rather gaining flexibility in when you can use them. Again keeping things tactically interesting, both of these conditions also prevent you from flanking (otherwise using an action now would usually be the obvious choice).
The arguments for this concept are compelling. You add tactical depth with the question: "is my action more valuable right now, in response to something that someone else did, or later on, on my turn?" Players pay more attention to the game during other turns because there's always the possibility of having an action being triggered. Combat flows more realistically and cinematically if creatures can act in response to what you do. Why should a creature be able to move across the entire battlefield without anyone reacting to it just because it's that creature's "turn?" Sure, all turns are supposed to happen simultaneously, but it creates some serious suspension of disbelief when the tactical landscape changes because of those actions. Why should a creature be able to move and then charge, covering 60 feet across open space toward a ranged enemy without risk of being hit by a volley during that movement? Furthermore, why should such a crazy move actually be advantageous, possibly leading to the ranged enemy being locked down? Would you run toward someone pointing a bow (or gun) at you?
The first new action presented in this chapter is Outpace. Triggered by a creature (ally or enemy) ending a move action in-motion and costing a move action (aka resulting in the Sapped condition), you can move yourself (albeit with some restrictions). This allows creatures to flee from enemies coming toward them, or to rush out to meet approaching enemies (perhaps to ensure the melee occurs in a more advantageous or less vulnerable position). The second new action is Interdict, which lets you make a Ranged Basic Attack as a standard action when an enemy completes a move in-motion, and if hit the triggering enemy is slowed, to boot. A powerful option, and one that speaks to the advantage that ranged attacks would logically have, but was previously absent from the game.
The "Run" action is another one that is tactically boring in 4E; not because using it is obvious, but because it's actually almost never a good idea to use at all. A heap of penalties for a measly speed bonus that, more often than not, isn't even needed. The rule has been outright replaced in Enhanced 4E, and to avoid confusion the new action is called Sprint. It carries similar penalties to being in-motion (and requires that you end in-motion), though it's a bit harsher. You open yourself up to attack from adjacent enemies (grant CA), suffer concealment penalties even with close and area attacks (though you have no net disadvantage attacking targets in your forward facing square), and have a limited turn radius. In exchange, you get the speed bonus like the old Run action, you won't provoke OAs from entering and exiting your forward-facing square (if you began the sprint in-motion), and most interestingly you enjoy total concealment against non-adjacent ranged attacks firing perpendicular to your line of movement. It's tough to hit a moving target!
Other refinements in this chapter are the Soar and Cruise movement types. These are basically just updates to the rules for flight speed and vehicles, respectively. Instead of simply allowing flying creatures to move just like terrestrial creatures - but in 3D! - the Soar rules more realistically model how a flying creature would move, mostly by imposing new restrictions on such movement. Plus the Hover trait means a whole lot more, now, since flying creatures need to move forward every turn and have a limited turning radius. If you care for such realism then these rules do a good job, but there's no denying that they add more crunchy complexity for something that usually doesn't come up that often in-play (thus they're not likely to be memorized by anyone). I've never had a problem with just "winging it" as a GM (pun intended), and having my flying creatures behave in realistic ways similar to these new restrictions. Much easier to do that in my book, but these new rules are great for simulationists, and they will even provide a good baseline for GMs who would rather improvise to do so in a more consistent manner. A useful addition even if you won't follow the exact rules to a T.
The new vehicle rules, including the Cruise movement type, utilize the new motion states (moving vehicles are not surprisingly always in-motion). They also outline various restrictions for turning radius and forced movement. Perhaps most importantly, a tiered system for acceleration (both positive and negative) is introduced. Most vehicles can't just start up at top speed from a dead stop (especially something like a horse pulling a carriage!), and Enhanced 4E offers fairly simple mechanics for it. There are also special in-motion rules for the vehicle's driver, and separate rules for any passengers. The example figures show a chase scene where a red dragon is pursuing a horse and cart with ranged PCs pelting the dragon from inside the cart. Some guidelines on using theater-of-the-mind for chase scenes would have been helpful here, as the double move requirement of Cruise along with typically high vehicle speeds would make tracking a course on a battle mat pretty complicated.
Active Defense and Counter-Offensives
In most games with active defenses a creature simply rolls opposed to the attack instead of having the attack compared with a static number. This increases variability, but not tactical depth, and many argue that the increased number of rolls slows play down. That's not how Enhanced 4E does active defense, and it's a good thing, too, with 4E combat already being comparatively slow.
The first concept introduced in this chapter is the "hit point healthy" value. Basically it's a complicated way of saying that everyone gets 3/4 HP if you want to retain standard combat length while employing the other rules in this chapter. These other rules tend to allow creatures to reduce incoming damage, or at least give them to option to do so. You can use HP healthy without the other rules to speed combat up, and you can ignore HP healthy while employing the other rules to draw combat out. Personally I think HP healthy is filled with a lot of pointless caveats and crunch because they also retain the max HP value and the two relate to each other in odd ways. As an example, a character who boosts surge value (through feats, items, etc.) would actually reduce his HP healthy value with the standard rules. Also, characters spend comparatively more time bloodied (which is still half of max HP). Fortunately, the simple houserule to this houserule is to call 3/4 HP your maximum, and perhaps provide a small boost to surge value (otherwise healing might get too low relative to the game's higher intrinsic damage).
In order to model a swashbuckling melee with constant movement creatures can make use of the Evade and Press actions. Evade is an off-turn move action (so you're Sapped) that a creature can make when targeted by an attack that targets AC or Reflex. You can move half your speed (the first square won't provoke OAs), and you can reduce some of the damage that was taken. Press, on the other hand, is a minor action taken on your turn. You can use it to follow an Evading enemy (even if you're not the one whom it's evading from), and it allows you to move half your speed minus one square (along the path that the enemy took). This is tactically critical, because if you end your press adjacent to the evading enemy you replace its Sapped condition with Tapped. Hello action denial! The speed differential ensures that an evading enemy can always move farther than a pressing creature of equal speed, and this has two consequences. The first is that allies will have to work together to set up Press opportunities for each other (and enemies that don't "take the bait" will give up their Evade, so you're denying actions either way). The example figures in the book made this look really cool, as it showed the turn-by-turn duel between a Fighter (set up by a Warlord) vs a Hobgoblin on a rope bridge. The second consequence of relative speeds of Press vs Evade is that faster creatures have a distinct advantage, which is something that is not usually apparent in combat (unless the extra speed is needed to cross some distance). The example that immediately springs to mind (because I tend to play them a lot) is an Elven Predator Druid. That speed 8 will allow the Druid to consistently catch up to evading enemies (of speed 7 or less) with the Press action, leading to more independently-generated action denial. Speed matters more overall, and faster monsters at higher levels will shift the dynamic in interesting ways.
Much simpler (and seemingly less tactically interesting) is the Brace action. It's an off-turn standard action that's triggered off of being attacked vs Fort or Will. A standard action is pretty costly just to reduce some of your incoming damage, and so this action will likely see much less use. Of course one consequence of this is that Fort and Will attacks become slightly more valuable because the active method of defending against them is more costly. Similar to the Brace action is Cower, the differences being it's triggered off of taking damage (as opposed to being targeted by an attack). You can also resist a square of forced movement. Situational, but good to have in your back pocket I suppose.
Collapse is a "no action" active defense that you can take if ongoing or automatic damage would drop you. You're instead left with 1 HP, prone, sapped, and tapped. The advantages are in not making death saves and potentially goading an enemy into wasting an attack to deal 1 effective point of damage (presumably before an ally heals you up afterwards). More interesting, however, is that Collapse can be employed by minions, which are often wiped out by auto-damage zones and auras in-play. Collapse means that they'll be locked down, but they can resume the fight as soon as the source of auto-damage is gone.
Finally, there's Ripost. Oh, what fun can be had with this action! It's triggered off of an attack that misses you, and for the price of an off-turn MOVE action you can make a Melee Basic Attack against your attacker. One interesting interaction is that multi-attacks like Twin Strike are taken down a peg; a Ripost can be taken if ANY individual attack in a power misses. Twin Strike always gave you double the chance of hitting at least once, but now you double your chances of triggering a Ripost too (and if you miss twice against two different targets you may trigger two!). This action is the main reason why a "free Melee Training" houserule is a very good idea. It's also worth noting that the ripost can trigger an Evade action, and the example figures show a dynamic sequence where the Fighter and Hobgoblin are constantly evading, pressing, and riposting each other, to different tactical effect depending on starting position and whether they or their opponent is already sapped or tapped. It all comes together into a set of organic options that don't boil down to "I use this power." Not that there's anything wrong with the power system, but it does tend to limit your viable options to what cards you're holding, and in Enhanced 4E that's no longer true. Besides, if these actions are hacked into a different system without specific powers, the increase in the amount of options might be even more significant.
The new rules in this chapter seek to expand the role of terrain in combat, and do so in a very simple way by providing mechanics for adjudicating modifiers. If the target of an attack has the high ground, your attacks vs Reflex and AC suffer a penalty. Likewise area and ranged attacks gain a bonus if the target is on low ground or significantly lower ground. If adjacent to a wall or other type of blocking obstacle a creature has support from it, and enjoys an effective bonus to Fort and Will depending on the size of the supporting object. Finally, the rules for Precarious Position mean that cliffs and pits aren't always dangerous when you take a fall, but also when you're adjacent to them. Some of your attention is always focused on not being subject to the adjacent terrain. Close and melee attacks against such creatures gain a bonus. Interestingly, occupying difficult terrain counts as being in a Precarious Position. That's cool, since powers that generate difficult terrain tend to be on the weak side (though there are some notable exceptions), and this is a nice buff.
Before I got to this chapter I thought that I had a pretty good sense of what this book offered, but boy was I surprised! Dramatic direction is more or less a new system for adjudicating initiative, and it's one that places fluidity and narrative flow at the forefront. It opens by describing two fight sequences from a hypothetical movie, scene by scene. Warrior swings sword, cut to opponent blocking, cut to warrior getting knocked onto the ground, etc. While there are exceptions to the pattern in most movies (usually used to create suspense), the general idea is that related scenes should follow one-another to preserve the causal relationships between them. Which doesn't happen in most turn-based RPGs where initiative is either determined by a die roll, or with all PCs going together and then all NPCs going together. To illustrate how such a structure would look if applied to a movie the individual scenes from the two different fight sequences were then mish-mashed together. While chronologically accurate perhaps, one can imagine getting a headache trying to make sense of everything if actually watching it.
Ok, so movies and RPGs are different, but it's not so crazy to strive for similar presentation between the two mediums. The Enhanced 4E argument is that dramatic tension is lost when an enemy responds to an attack on his randomly-determined turn, in which 10 minutes of real-time may have passed. Even more off-putting are the effects that initiative order can sometimes have that strain suspension of disbelief. The example used (and a very good one at that) is a knight getting knocked off of his mount, and then because his turn arrives before the mount's he stands up from prone, remounts, and continues on as if nothing major happened. But the model fails to depict the game world here; that horse should be dozens of feet away before the knight can even get to his feet, and he's going to have to deal with the consequences of being dismounted, even if the horse turns back for him.
To solve these problems, mechanics for assigning priority in the initiative are provided. Initiative is still rolled and is still important for determining who will act first in the encounter, but the exact order will frequently be altered in order to preserve the narrative flow.
The first "cue" is Called to Action. If you're targeted by a close, melee, or grab attack and you haven't acted yet, your turn will occur immediately after your attacker's. This will tend to clump the action into spatially (and narratively) relevant groups. Fighter rushes up to the goblin shaman, you immediately see how that shaman responds. Cause and effect. That section of the battlefield is resolved, move onto another set of opponents. It certainly makes sense to me. As a GM I don't enjoy taking the unrelated turns of a group of enemies in rapid-fire succession (goblins 1 and 2 are attacking the warlord, goblin 3 is heading over toward the wizard, and goblin 4 is going to continue to attack the fighter, etc.). I'm not picturing the action very well when I do this (and the same probably goes for my players); rather I'm just trying to get all of these turns over with as fast as possible to keep the PCs engaged. Why break the action up into fragments of scenes if you don't have to? You're trying to tell a story here!
Keep Rolling is a dramatic direction that places creatures that are in-motion at the top of the initiative order. Such creatures haven't completed their full, in-game action; their scene isn't "finished." It makes most dramatic sense to resolve that scene (which is implicitly action-charged) as soon as possible. It also makes sense to establish what's going on with a vehicle during the current round before having its passengers take their turns. You could also argue that their momentum gives them a physical, in-world "edge," putting them where they want to be slightly faster than those who are motionless.
Finally, creatures that are immobilized or knocked prone are Held in Suspense. This neatly solves the "knight falls off his mount" conundrum. If you haven't taken your turn yet, you move to the top of the initiative for the next round. Why not the bottom of the current round? Because the Keep Rolling rule allows creatures in-motion to take priority, moving to the top of the initiative AFTER you've been placed there. Prioritizing the initiative this way models the fact that if you've been knocked to the ground while others continue to move, they're going to gain some distance on you. Initiative order shouldn't serve as a loophole to get around that.
So is the book worth picking up? I'd say definitely, yes. While it would seem to target an extremely niche market (players of D&D 4E, an edition soon-to-be-replaced, who want more tactical complexity from an already tactically-complex game), it does hold a wider appeal to more than just that niche. While the book is explicitly a set of house rules for 4E specifically, what I found most interesting were the game-design implications of its more novel concepts. Dramatic directions make so much sense I'm surprised I haven't encountered them before. They show that you can make this small tweak to a fairly minor mechanic (initiative) in order to create a specific style of play (more cinematic and consistent action sequences). Add to this the freedom that the new off-turn actions allow and you're no longer constrained by the restrictions of turns and initiative order, despite the fact that you're not abandoning those systems (which exist to give the game structure and actually make it playable). The additional rules complexity seems to be minimal, and the way in which combatants organically respond to each other is a huge reward, providing access to a whole new style of play. The chapter on active defenses illustrates new ways in which both PCs and monsters can gain control over their defensive stability vs offensive output, and the discussion of these options relative to HP healthy values provides a good starting point for GMs to start thinking about how they can alter the speed of combat and lethality in their games.
With D&D Next (5th Edition) on the horizon, it's also nice to know that third-party publishers can still breathe life into 4th Edition, perhaps even after WotC stops supporting the system. Indeed, I'd argue that the fresh and drastically different perspective offered in this book is a much better addition to the game than a lot of the official WotC stuff (how many "X Power" or "Adventurer's Vault" style books do we really need?).
As I was going through the book, I kept the possibility of system conversions ever-present in my mind. Lately I've been drawn more and more toward 13th Age and somewhat away from D&D, and so it was often the consequences of using these rules with that system that occupied my thoughts. Despite it being theater-of-the-mind by default, many of the concepts of Enhanced 4E can be distilled down, tweaked, and applied to 13th Age. In theory, at least (the caveat is that I haven't playtested these rules, nor have I even played 13th Age yet for temporary lack of a gaming group!). Still, it illustrates an important point because 13th Age is rules-light, somewhat freeform, fast-paced, and gridless (all things that 4E is not). Indeed, new tactical modules might be even more attractive for such a system since its burden of complexity is already low enough that new options would be unlikely to push it over the edge.
Ultimately, the biggest strength of tabletop RPGs is that they can greatly facilitate the ability to match the game and its rules to the group. In other words, they let you play the game that you want to play. A book packed with so many novel concepts can therefore be a great font for new ideas. Combat In Motion offers a new perspective, and one that will get you thinking about how to best run the game you want to play.