Chase Scenes
Chase scenes are a staple of the Eberron campaign, just as much as combat is. The Chase rules (GG, pg. 232) are a decent start, however their use fails apart at higher levels, with access to extradimensional travel, and does not accurately take into account alternate modes of movement (climb, swim, burrow and fly). As such, the following is the modifications I recommend to keep them useful at higher levels.
Chase Scene Definitions
Chase scenes are run like a normal combat encounter. Initiatives will need to be taken and the participants (party members and NPCs) act in the normal order. The rules for combat remain in effect during a chase scene, although much of the actions taken will be to move closer to the finish line or another participant. In order to set up a chase scene, there are some definitions and modifiers that need to be determined first. I recommend writing these down somewhere for quick reference for each participant in the case.
APL: Average Party Level. Exactly the same as in the core rules.
Movement: Each participant needs to determine their movement rate under the following conditions. Keep in mind class abilities, feats and other special options when determining the participant's movement rates. Note that participants on mounts use their mounts movement rates for the following.
Land - Regular: This is the land movement rate of the participant with a single move action
Land - Run: This is the land movement rate of the participant while taking a run action. This is normally their regular movement rate x4, but options like heavy loads and the Run feet can change this to either x3, x4 or x5.
Climb - Regular: This is the climbing movement rate of a participant with a single move action. This is normally 1/4 of their land movement rate, but participants can use accelerated climbing (1/2 of their land movement rate with a -5 penalty, not a good idea with those less than 100' land movement). Those with a climb speed will have their own climb movement rate.
Climb - Run: This the climbing movement rate of a participant with a double move. If someone can use a run action while climbing, something that even those with normal climb speeds cannot do, then this would be their climb speed x3, x4 or x5, as appropriate.
Swim - Regular: This is the swimming movement rate of a participant with a single move action. This is normally 1/4 of their land movement rate, but participants with a swim speed will have their own swim movement rate.
Swim - Run: This is the swimming movement rate of a participant taking a run action or a double move. This is normally 1/2 of their land movement rate, but participants with a swim speed will be either x3, x4 or x5, based on heavy loads and the Run feat.
Fly - Regular: This is the flying movement rate of a participant with a single move action
Fly - Run: This is the flying movement rate for a participant while taking a run action. This is normally their regular movement rate x4, but options like heavy loads and the Run feet can change this either x3, x4 or x5.
Burrow: This the burrow movement rate of a participant with a single move action.
Zone: A chase scene is made up of a number of zones (minimum 3). Each zone represents a different part of the terrain that the chase scene passes through. Each zone is linked to one or more zones after it, allowing for chases scenes that are both linear as well as multi-routed. In most chase scenes, a single zone is designated the Start Zone and another is designated the Finish Zone, although complicated chase scenes can have multiples of either. The nature of future zones (their order, details etc), do not have to be known to all participants at the beginning of the chase scene, but the nature of the zone a participant is in is known to him the movement he enters the zone.
Zone Checks: Each zone has at least two different checks needed to leave the zone. A participant only needs to make one of these checks, but, in the case multi-routed chase scenes, the check chosen will determine which zone the participant will be entering. Each check has a required action that needs to be spent and a specific check that needs to be made in order to leave the zone.
Zone Consequences: A zone may have certain consequences for successful or failure for one or more of its zone checks. The most common zone consequence is each zone check leads to a different zone further along in the chase scene. Occasionally, a zone consequence might require the participant to move to a specific zone if a check is failed (particularly for failing a climb check by enough to fall). If the terrain itself is chaning, a zone consequence might only go into effect after a certain number of rounds or a certain number of participants enter the zone (like outrunning an avalanche or a bridge collapsing under too much weight). The specifics of a zone consequence are detailed for the zone.
Zone Cover: The relative cover bonus provided against ranged attacks from outside of the zone (see below)
Zone Type: There are three kinds of zones, Standard, Dead Sprint and Complex. A standard zone is always linked to one zone before it, the exception of the Start Zone, and one zone after it, with the exception of the Finish Zone. It always two zone checks to leave the zone and never has any zone consequences. A Dead Spint Zone is a special kind of zone that is always linked to one zone before it and one zone after it, but only has one type of zone check and one specific kind of zone consequence, detailed below. Complex zones are always linked to the zone before it, but can be linked to multiple zones after it. For every zone after it that it is linked to, there is at least one zone check to enter that specific zone. Complex zones can also have their own consequences.
Zone Range: The relative width and length of the zone. By default, each dimension is equal to the average land movement rate of all participants. Dead Sprint Zones have a much larger zone range.
Zone Checks
As mentioned, each zone has two or more zone checks needed in order to leave the zone. The action needed to leave a zone and the type of check needed is set by the GM, using the normal DCs for that kind of check. However, these checks are modified as detailed below.
Types of Zone Checks
There are many different kind of zone checks that are used in chase scenes. Chief among them are Acrobatics and Climb checks, but other kind of checks (other skills, saving throws, combat maneuver checks, attribute checks) can all be used. It is important that no zone has more than one instant of the same kind of check. Likewise, there should always be a difference of at least 5 between the DCs of the different zone checks (with attribute checks usually being the lowest and skill checks usually the highest).
Zone Check Modifiers
Zone checks can be any kind of check, although skill checks and saving throws are the most common kind to you. They are handled just like any other checks, with DCs appropriate for the situation, but with the following modifications
Movement Modifier: For each of the above movement rates, each participant gets a +1 movement modifier per 5' to any check made to advance in a chase scene. Situations that improve someone's movement rate do apply to the movement modifier, at the normal +1 per 5', for the turns that it normally apply. Which modifier used is determined by the check needed to leave a particular zone (Climb for Climb checks, Swim for Swim checks, etc), but the default modifier is the Land - Regular.
Pace Modifier: The GM determines the overall pace of the chase scene, which is usually the average regular movement rate of all participants. For each 5' of this average, the GM assigns a +1 pace modifier to the DC of each check needed to leave a particular zone. It is important to note that if a particular check cannot be made above a particular DC (like Knowledge checks over DC 10) or would have a disastrous consequence (such as failing a Climb check DC by 5 or more causes falling), the pace modifier to the DC is NOT factored into this. Thus, if someone gets a result of 18 on a Climb check that is normally a DC 20, but the pace modifier would make it a DC 25, that participant would not start falling. It is for this reason that voluntarily taking penalties to checks, like accelerated climbing must reduce the final die result and not increase the check DC. Likewise, if a pace modifier would turn a Knowledge (local) check from DC 10 to DC 20, it can still be attempted untrained.
Zone Check Actions
By default, in order to leave a zone, you must spend a standard action on one of the zone checks detailed on the zone and, if successful, spend a move action to leave the current zone and enter the next zone. If the check is unsuccessful, the participant remains in that zone, unless stated otherwise by the zone consequence. A participant is not required to attempt a Zone Check if he wishes to remain in that zone. There is one special kind of zone that this handled different.
Dead Sprint Zone: A dead sprint zone is handled specifically by an all-out, straight-line run. Dead Sprint Zones represent a much larger area of terrain than a typical zone in the same chase scene, often five times the normal space or more. Dead Sprint Zones also only have one kind of Zone Check to be able to leave them. In order to leave a Dead Sprint Zone, you must clear the total distance of the zone. This is usually handled by using one or more full-round actions to run or a series of double move actions. If successful, the participant only needs to spend a free action to leave the Dead Sprint Zone.
The check itself for a Dead Sprint Zone is usually a Strength check for participants with natural movement rates. Participants with mounts, or using vehicles powered by mounts, use the mount's Strength modifier for the Strength check. Multiple mounts do not give any Aid Another benefit, unless there are more mounts than what is needed for the vehicle. Participants using spells, spell-like abilities, psionic powers or psi-like abilities to give themselves a movement rate they do not normally have use the casting or manifesting attribute instead. Participants with magical items that give them a movement rate they do not normally have use 1/4 of the item's caster or manifester level, rounded down. Participants using vehicles that do not use mounts use their Wisdom instead.
Regardless of the type of check used, the DC for a Dead Sprint Zone is equal to the distance covered by the Dead Sprint Zone, divided by 5, rounded up, plus the pace modifier. Because the Strength check DC of a Dead Sprint Zone can be very high (often exceeding DC 50), failing the check has a unique consequence. For every 5' of movement you have already spent in a Dead Sprint Zone, you get a +1 movement modifier to any related Strength check to leave the Dead Sprint Zone. Thus, if someone failed the initial Strength check to leave the Dead Sprint Zone and ran a total of 90 feet, on the following turn, he would get a +18 movement modifier bonus to the Strength check to try again. If he still failed and ran another 90 feet, the movement modifier would be a +36 and so on. Once he has finally left the Dead Sprint Zone, this temporary movement modifier would be lost.
Combat During Chase Scenes
It is possible, even likely, that during a chase scene, some combat will occur. Melee combat can only occur between participants that are in the same zone. Ranged combat can occur between different zones but with the following rules.
Zone Range
Each zone represents a set amount of terrain with a width and length, usually equal to the average movement rate of the participants. Each zone is assumed to be adjacent to zones immediately before and after it. With the exception of Dead Sprint Zones, participants are assumed to be in the center of the zone they are in. Those in Dead Sprint Zones are a number of feet into the zone equal to the total number of feet they have moved while in the Dead Sprint Zone. From this, a finite range can be determined by totaling the distance between one participant to the edge of their zone, the distance covered in the zones in between and the distance from the edge of the other zone to the other participant.
Factoring the distance betwen zones that are not adjacent, but parallel, on multi-route chase scenes will require GM adjucation.
Zone Cover
With the exception of Dead Sprint Zones and zones that in unusually open environments, each zone provides a certain amount of cover to ranged attacks made from outside of that zone. If there is more than one zone between you and your target, apply the most severe kind of cover. For ease of reference they are detailed here.
Open: No cover. Examples of this environment would open plains, deserts and other areas that you can see for miles clearly.
Default: Partial cover (+2 to AC, +1 to Reflex saves). Examples of this environment would be lightly forested areas, farmlands or other areas that you can see for hundreds of feet clearly
Cluttered: Cover (+4 to AC, +2 to Reflex saves). Examples of this environment would jungles, forests, small towns and other areas that you can see for tens of feet clearly
Crowded: Improved Cover (+8 to AC, +4 to Reflexes). Examples of this environment would be dense jungles, dense forests, large cities and other ares that you can see unobstructed for only a few feet
Closed: Total cover (cannot be targeted). Examples of this environment would be most dungeons, crowded cities and metropolis, building interiors and other areas that you are regularly obstructed.
Unusual Movement During Chases
Because options like extradimensional movement, flying, burrowing can create new options for participants they are detailed here.
Extradimensional Movement
With options like extradimensional movement available to higher level characters, it is possible entirely skip one or more zones during a chase scene without the appropriate checks in between. Using extradimensional movement takes the same kind of action that it normally does, but all extradimensional movement requires knowledge of the target location. In situations where the participant has nothing worse than Partial Cover (as per Zone Cover) between the zone he is in and the zone he wants to go to, this can be assumed as line of sight. If the worst Zone Cover between his zone and the zone he wants to go to is Cluttered or Crowded, he needs to make a Perception check, DC 10, modified for range and visibility, to be able locate a spot that would still qualify as line of sight. Closed zones block line of sight out of or through their zone.
If the participant does not have line of sight as to where he wants to go, he needs to visualize where he wants to go. For spells that already have a chance of choosing the wrong location, use those rules. For others that do not, the participant needs to make an appropriate Knowledge check, usually Architecture (for buildings), Dungeoneering (for underground), Geography (for outdoor environments) or Local (for cities). The DC for this equal usually 20, but can change between 10 to 40, based on how well the participant knows the area. If this check fails and the target zone is either Open or Default (as per Zone Cover), he arrives in an zone adjacent to his intended one. If the target zone is Cluttered or Crowded, he arrives in an adjacent zone and is considered shunted by 100 feet or less. If the target zone is a Closed zone, he arrives in an adjacent zone and is considered shunted by between 101 to 1,000 feet.
If the participant is chasing someone and wants to be in the same zone as they are, he also needs to succeed on either a Perception check (he has line of sight) or Sense Motive check (if he does not). The DC for the Perception check is 10, modified for range and visibility (and opposed by Stealth if appropriate). The DC for the Sense Motive check is DC 20, but then requires the appropriate Knowledge check for extradimensional movement without line of sight.
Note: If extradimensional movement is used to completely escape a chase scene, then the chase scene ends.
Note: Failed extradimensional movement is a way to make new zones (See Below).
Making New Zones
With options like a fly speed or a burrow speed, it possible for some participants make new zones where they did not exist. For example, not every participant can make a particular kind of check (like a vehicle against a Climb check) and needs to take the long way around, or the person in lead has no idea of where he is going and thus is making up new zones with each new zone he enters. Regardless of the reason, each new zone created will always need to be linked at least one existing zone. See Setting Up a Chase Scene for determining a new zone. If a player is creating a new zone, see Setting Up a Chase Scene, but use the Randomly Determining Zones rule.
Moving Zones
Some zones may move during the course of a chase scene, changing which zones they are linked to and from. A good example is a chase scene near a lightning rail terminal and zones covering different lightning rails coming into and out of the station. Alternately, a chase scene primarily handled on a lightning rail would have stationary buildings act as moving chase scenes. The key is determine what the core of the scene is representing and if the zone in question is moving in relation to the chase scene as a whole. While the actual movement of the moving zone can be determined by its movement rate versus the average zone range, it is recommended that a moving zone change the zones it is linked to and form no more than once per round.
Participants cannot control a moving zone. The moment they do, the moving zone becomes a new participant or a vehicle for the existing participant, as needed.
Skipping Zones With Movement
Skipping over zones with unusual movement rates, like flight or burrow requires the creation of one or more new zones. In order to skip one or more zones, first the participant must be able to leave the zone he is currently in. Next, he determines which zones he is trying to skip, noting the number of zones and their relative position to each other on a real map (above, below, etc). The participant must then either enter a Dead Sprint Zone, covering the total distance between the zone he is leaving and the one he wants to enter, pass through a number of zones equal to the relative distance between the two zones, divided by the average participant land movement rate, or some combination of the two. The exact combination is based on GM's discretion and environmental factors, but it is common to have a single Dead Sprint Zone for fly and burrow speeds.
Setting Up a Chase Scene
To set up a chase scene, first you will need to determine the basic environment, the participants and the average participant movement rate. This gives you the base zone range for each zone, the overall movement modifiers the participants will be using and the pace modifier to modify the DCs for the zone checks. Next, you will need at least one Start Zone and one Finish Zone. In between, you need at least one other zone, for a total minimum of 3.
Start Zones
Each participant starts at a Start Zone. They do not all have to start at the same time. If one participant has a lead, then they would start a number of turns ahead of the rest, making their way through zones as needed. If you are making a complicated chase scene with multiple Start Zones, then each participant would begin on the zone assigned to them. Start Zones have the same possibility for zone checks, zone range, zone cover, etc as normal zones.
Finish Zones
Each chase scene has one or more Finish Zones. Like other zones, Finish Zones have zone checks, zone range, zone cover, etc as normal zone. When a participant manages to successfully leave a Finish Zone, they are no longer part of the chase scene. If the nature of the chase scene is to catch one or more participants before they leave a Finish Zone, then the chase scene ends when all of the chased participants have left a Finish Zone.
Determining the Zones
Once you have your start zone and finish zone, you then need to populate the area in between with zones. Each chase scene has to have a minimum of 1 zone inbetween the Start Zone and the Finish Zone. The average number of zones between a Start Zone and a Finish Zone determines the length of the chase scene. Below are the recommended number of total zones for different kinds of chase scenes. Remember that, on average, a chase scene will last for a number of rounds equal to total number of zones.
Once you have determined the total number of zones you want and have the base zone range, you will then need to detail each zone. Start with the first Start Zone. Decide on the general concept for the challenge of this zone. Detail the zone range and zone cover, based on the environment. Then, choose if the zone will be a Standard Zone, a Dead Sprint Zone or a Complex Zone. If the zone is a Standard Zone, choose two different kinds of checks and set the DCs for them. If the zone is a Dead Sprint Zone, then determine the extended zone range, which will determine the DC for the only check for the zone. If the zone is a Complex Zone, then choose a minimum of two different kinds of checks and set the DCs for them. Decide if the Complex Zone will have a complication, what that will be and the circumstances for triggering and notate whether or not the Complex Zone will link to more than one zone later. Repeat this process for each zone
Determining Zone Checks
When choosing the zone checks and the DCs for them, it is important to use the existing rules for the type of checks. If you are climbing up a wall, the Climb DC will be determined by the kind of wall. If you are jumping over a pit, then the Acrobatics DC will be determined by the length of the pit. Only after you have determined the specifics of that the DC would be outside of a chase scene do you apply the pace modifier to the DC for each zone check. When determining the kind of checks and the DCs involved, it highly recommended that the two checks not be based off of the same attribute and the DCs for each be different by at least 5. Certain types of checks are more common than others during a chase scene, but any kind of check you can think could be used. Here are some examples. The recommended DCs are before applying the pace modifier.
Common Checks (Recommended DC: APL +15-20): Acrobatics, Climb, Bull Rush Maneuver, Escape Artist, Feint Maneuver, Fly, Knowledge (local or geography), Overrun Maneuver, Perception, Profession (driver), Ride, Swim
Uncommon Checks (Recommended DC: APL +10-15): Bluff, Diplomacy, Disable Device, Dirty Trick Maneuver, Fortitude Save, Intimidation, Knowledge (dungeoneering, engineering or nature), Reflex Save, Reposition Maneuver, Sense Motive, Steal Maneuver, Strength check, Trip Maneuver
Rare Checks (Recommended DC: +5-10): Any other check not listed
Note: Do not put more than one type of check that cannot be made untrained. Remember that the pace modifier does not affect what skill checks can be attempted untrained.
Note: As Strength checks are commonly used for the Dead Sprint Zones, it is recommended not to use them for other types of zone checks, except where lifting is important.
Note: It is very easy to use Acrobatics as one the zone checks in every zone. Do not do this. While it is the most common skill used in chase scenes, those with a high Acrobatics skill should not be garaunteed to win every chase scene.
Note: If you are going to use saving throws as a zone check, consider keeping them to Complex Zones where failure triggers a zone consequence.
Determining Zone Complications
Determining zone complications can be more work than determining the zone check related to it. In most cases, failing the check should only penalize the participant for one full round (via getting lost or getting nauseated) or by moving the participant into a zone he doesn't want to be it (one zone back or one zone on a different branch of a mult-routed chase scene). If the zone complication is more complicated than that (deals damage, poison, etc), treat this as a a trap or hazard of a CR appropriate to the APL.
Randomly Determining Zones
In order to randomly determine a new zone, follow these steps. Repeat as necessary.
Start with determining the zone that will link to this new zone. If this new zone a Start Zone, then choose the zone that it will link to. This is considered your base zone
Determine the zone cover of your base zone and the average zone range of chase scene
Roll d6. The zone cover of the new zone will either be one step above (1-2), equal to (3-4) or one step below (5-6) the zone cover of your base zone.
Roll a d100 and compare on the table below determine the type of zone, based on its zone cover. If the zone is a Standard Zone or a Complex Zone, the zone range will be equal the average zone range. If it is a Dead Sprint Zone, then the zone range will be equal to the average zone range times the result of a d10.
Once you have determined what kind of zone it is, determine the zone checks
For Standard Zones, choose two common checks (listed above) that do not use the same attribute. Set one DC to APL +15 and the other DC to APL +20 and apply the pace modifier. Make sure that at least one of the two checks can be attempted untrained.
For Dead Sprint Zones, the DC is already set by zone range plus the pace modifier.
For Complex Zones, determine the following
Roll d4: 1) This zone will link to one new zone. 2) This zone will link to two existing zones. 3) This zone will link to one existing zone and one new zone. 4) This zone will link to two new zones.
Roll d4: 1) There is no zone complication. 2-3) Failure on a zone check will delay a participant for 1 full round. 4) Failure on a zone check means a trap or hazard of a CR appropriate to the APL.
Choose one uncommon check or one rare check (50%/50%) for each zone that this one will link to, minimum 2. Set all DCs to APL +10 and apply the pace modifier. Make sure that at least one check can be made untrained.
Link the new zone to the appropriate zones before and after it. The only exception for this would be new Start Zones do not have a zone before it.
Hidden Zones
As mentioned, the details of a zone may not be known by participants until they are actually in that zone. For this reason, I recommend detailing the individual zones on 3x5 index cards and leaving those that are hidden face down until the first participant enters that zone. The moment that there is no one in that particular zone, flip it back face down again.
Chase Scenes as Encounters
Chase scenes should feel like combat encounters, with the fast past nature of things. However, determining the total EL of a chase scene can be a little tricky. You must assess the chase scene after it has ended before you can determine it's EL, using the following factors.
The chase scene itself would have a base EL based on the length of the chase scene that was actually covered.
# of Zones covered < APL: CR -2
# of Zones covered >= APL, but < 2x APL: CR -1
# of Zones covered >= 2x APL: CR
If actual combat occurred during the chase scene, the EL for the combat is included in the total EL of the chase scene
If any Complex Zones had traps or hazards and those traps or hazards were actually triggered, the CR for those traps or hazards are included in the total EL of the case scene.
In what would be an exception to the general rule of awarding party members XP for situations that they cleverly avoided, avoiding all or part of a chase scene does not award XP for the parts that were skipped. The reasoning behind this is that avoiding a chase scene and taking the combat some place else is like separating a group of monsters into two groups, defeating one group and not touching the other.
Chase Scene Template
Here is the template I use for 3x5 index cards when I am setting up a chase scene, to give a idea of how best looks to the players. I have placed a beta test chase scene generator here.
