CHASES

Role-playing games regularly involve action and chases are a common occurrence. The following rules provide a dynamic mechanic for handling chases in a Anime d20 game.

During a chase, one mecha (or sometimes one character) — the “predator” — is assumed to be trying to catch the other — the “prey.” The predator and prey may be flying, running, driving, swimming, or engaging in almost any other conceivable method of movement. For conciseness, the wording of these rules assumes that both predator and prey are in mecha, though it can apply equally to characters on foot or riding mounts of some kind. These rules work just as well for chases on horseback as they do for vehicle chases.

TERRAIN

The GM and players should have an idea of the terrain in which a chase is taking place before getting started. Terrain establishes the general conditions of a chase, as well as obstacles to be avoided.

OPEN TERRAIN

Open terrain is easy to traverse, with only slight changes in elevation and few imposing obstacles. Examples are: wide, flat plains; large, open areas with few obstructions; clear skies at high altitude; open seas; racetracks; highways.

In open terrain, the speed of the chase begins at three-quarters of the maximum speed of the fastest mecha involved (rounded down). Open terrain chases in which one mecha’s maximum speed is less than threequarters that of its opponent are usually over before they start.

A mecha’s maximum speed is critical in open terrain, and the mecha with the highest speed receives a +2 speed bonus to all Drive checks. If only one mecha in the chase is considered to be in open terrain (either due to two or more types of terrain, Feats, or mixed movement types) then that mecha automatically receives the +2 speed bonus. By its very nature, open terrain contains few large, hard obstacles.

The GM should roll 1d10 each chase round which occurs in open terrain — a result of 1 indicates an obstacle of DC 12 (see Obstacles, page 144). Even if a collision occurs in open terrain, mecha usually carry on with little or no damage. Critical failures in open terrain are particularly bad, however, as the mecha involved are typically moving as fast as possible.

CLOSE TERRAIN

Close terrain is generally narrow and filled with plenty of stuff to run into, clip, and burst through. Typical examples include narrow alleys, open areas with many obstructions, or air combat at low altitudes.Due to the difficult conditions, the speed of a chase in close terrain begins at one-half of the fastest mecha’s maximum speed (rounded down). The GM should roll 1d10 each chase round which occurs in close terrain — a result of 2 or below indicates an obstacle of DC 18 (see Obstacles, page 144).

TIGHT TERRAIN

This is the most dangerous of all terrain, filled with sharp drops and large, dense obstacles. Typical examples include stairways, corridors, busy highways, boulder-strewn areas, whitewater rapids, and aerial battles at treetop levels.

In tight terrain, the speed of a chase begins at one-quarter of the fastest mecha’s maximum speed (rounded down). Such close quarters favour highly responsive mecha, and so if both predator and prey are in tight terrain, the mecha with the highest Manoeuvre value (or the mecha suit whose pilot has the highest Dexterity) gains an additional +1 speed modifier to all Drive checks.

Tight terrain is unstable, and mecha in these areas should be prepared for anything. The GM should roll 2d10 each chase round that occurs in tight terrain — a resultn 5 or below indicates an obstacle of DC 24 (see Obstacles, page 144).

INITIAL LEAD

Speed to Speed
Base Speed	Actual	Move Action
30ft	3 mph	3
40ft	5 mph	4
50ft	6 mph	5
60ft	7 mph	6
100ft	11 mph	10
150ft	17 mph	15
1: In space all values are doubled

The distance between mecha during a chase is called the “lead,” and is measured in lengths. In most cases, one length equals 10 feet. The GM should adjust the size of the length depending on the conditions of the chase. For example, a chase between two aircraft might use lengths of 100 feet while a fight between two starfighters might be measured in 1,000-foot lengths.

At no time can the lead be less than zero or greater than 30. If any effect reduces the lead to less than zero, the lead becomes zero. Similarly, if any result increases the lead above 30, the lead becomes 30.

Each round depending on how much of your movement you invest in speed you may add your speed to your current speed in order to increase the total.

Chases can start in a number of ways, but most boil down to one of two categories: predator-initiated and prey-initiated. This determines how much of a lead the prey has at the start of the chase. When the predator begins a chase, the initial lead is equal to 2d6+3 lengths (usually 50 to 150 feet). When a chase begins with the prey fleeing, the initial lead is 2d6+8 lengths (usually 100 to 200 feet). If there is no clear initiator in a chase, both sides roll Initiative and the highest result is considered to have started the chase.

CHASE SPEED

Chase speed is measured in miles per hour and is determined by terrain at the start of the chase. Chase speed changes throughout the pursuit according to the manoeuvres chosen by the mecha each round. Whenever the chase speed exceeds the maximum speed of one of the mecha at the end of a chase round, the mecha is dealt +2 damage. This damage is not reduced by Armour or other effects, and is in addition to all damage caused by manoeuvres, crash checks, and other effects.

CHASES: STEP BY STEP

There are six steps to chases, which are explained in broad strokes here and then in detail in the following sections. These six steps continue in cycles until the chase ends — either with the capture or escape of the prey.

STEP 1: CHOOSE MANOEUVRES

Each mecha (or group of mecha) secretly chooses a manoeuvre from the list offered. Each manoeuvre has strengths and weaknesses, and is usually geared towards a specific goal.

STEP 2: DRIVE CHECKS

The mecha operators make opposed Drive checks (or other appropriate checks for non-mecha; Ride, Tumble, Swim, or Climb, for example). The winner’s manoeuvre succeeds.

STEP 3: RESOLVE MANOEUVRES AND ADJUST LEAD

The effects of the manoeuvre that succeeded are applied, and the number of lengths between the mecha is adjusted.

STEP 4: OBSTACLES

The GM rolls for obstacles.

STEP 5: OTHER ACTIONS

Assuming the chase continues, each passenger of each mecha may perform a full action or a move and a standard action. An operator may perform either a move action or a standard action in addition to operating the mecha, but receives a -4 penalty to the next mecha operation-related check or roll (such as a Drive check or attack roll) if he or she does so.

STEP 6: DAMAGE AND COLLISIONS (IF ANY)

If warranted, mecha operators make Drive checks to see if their mecha have collided with anything.

STEP 1: CHOOSE MANOEUVRES

The first step during each chase round is choosing manoeuvres. There are two types of manoeuvre: predator and prey.

Due to the abstract nature of chases, the distance covered and the specific locations of each mecha are left up to the imaginations of the GM and players. What’s important is the distance between them at any given time. The initial lead is determined as part of getting started, but should be rechecked at the start of each round. Many manoeuvres may only be chosen by mecha with a certain minimum or maximum lead.

Ultimately, the goal of the predator is to decrease the lead enough that it can perform one of the finishing manoeuvres (see below) and catch the prey, while the prey is trying to do a finishing manoeuvre that allows it to escape. Chases continue until either the predator or prey successfully performs a finishing manoeuvre, someone crashes, or one of the mecha is disabled (see Step 6).

MANOEUVRE DESCRIPTIONS

The following elements go into the description of each manoeuvre. The GM may modify or disallow certain manoeuvres depending on the specific circumstances of the chase.

Lead: Minimum or maximum distance between predator and prey required to perform the manoeuvre.

Speed: Succeed or fail, both the predator’s and prey’s manoeuvres may modify the current chase speed. If both predator and prey choose manoeuvres that alter the chase’s speed, only the highest modifier (positive or negative) applies.

Success: The effects of the manoeuvre, when the mecha that chose it wins that round’s opposed Drive check.

Special: Any additional information or conditions.

PREDATOR MANOEUVRES

Each round the predator should write its manoeuvre down on a piece of paper and keep it secret. Predator manoeuvres are geared toward slowing down or catching the prey.

BOX IN (FINISHING)

It takes skill to trap an opponent with minimal damage.

Lead: 5 lengths or less.

Success: The predator wins the chase, forcing the prey into a corner from which there is nowhere to run.

CROWD (FINISHING)

Crowding is getting right up into the prey’s backside and forcing it into a collision with the environment.

Lead: 2 lengths or less.

Success: The predator wins the chase by forcing the prey into an obstacle. If the predator’s Drive check exceeds the prey’s by at least five, the prey collides with an obstacle of the GM’s choice. The prey is treated as though it failed a crash check (see Step 6). If the predator’s Drive check exceeded the prey’s by less than five, then the prey may still make a crash check to avoid a damaging collision, though the chase is still over as the vehicle is forced to stop to avoid the collision. The predator, regardless, stops safely.

CUT OFF (FINISHING)

Without warning, the predator speeds up and pulls out in front of the prey, cutting him or her off. The predator’s mecha becomes a barrier to stop the prey from escaping.

Lead: 0 lengths.

Speed: Chase speed is reduced by 25 mph this round.

Success: The predator wins the chase. If the prey fails its Drive check, it collides with the predator; no crash check is required. Damage is applied to both mecha, as per the Step 6 directions.

GUN IT

Gun It is the basic predator manoeuvre, in which the predator attempts to catch up with the prey in a straightforward manner.

Lead: Any distance.

Speed: Increase the chase speed by 10 mph this round. Success: The lead is reduced by a number of lengths equal to the difference between Drive checks.

HERD

Forcing the prey to make bad choices can be as effective as chasing him down. By keeping the pressure on and cutting off the prey’s options, the predator uses strategy and brute force to drive the prey into dangerous situations.

Lead: 10 lengths or less.

Success: The lead is reduced by one length and the prey is required to make a crash check, with a DC determined by the chase setting and increased by the difference between the Drive checks. The predator must also make a crash check this round (with no additional penalty).

Special: By beating the prey’s Drive check by five or more, the predator may choose to reduce both the predator and prey’s crash check DCs by five to shift the terrain by one step at the end of the round (open or tight becomes close and vice versa). Alternatively, the predator may ignore the crash check.

JOCKEY (VEHICLE ONLY)

By carefully matching the prey’s movements, the predator can force the relative speeds of the two mecha down to almost zero, stabilising the chase so that others in the vehicle can attack.

Lead: 10 lengths or less.

Success: The lead is reduced by one length and the driver and all passengers in the predator vehicle gain half the difference between the manoeuvre checks (rounded down) as a bonus to their attack rolls targeting the prey.

RAM (FINISHING)

Ram is straightforward: the predator speeds up and slams into the prey, forcing it off the road. It’s dirty, but often gets the job done a lot faster than Crowd.

Lead: 5 lengths or less.

Success: The predator wins the chase, colliding with the prey. Both mecha are treated as though they failed crash checks (see Step 6). They then come to a halt.

REDLINE

Redline is an advanced version of Gun It, during which the predator suddenly accelerates to and remains at its top speed. This causes incredible wear and tear on the mecha as its power plant literally burns up (or an animal strains itself, etc.).

Lead: Any distance.

Speed: Increase the chase speed by 20 mph. Success: The lead is reduced by a number of lengths equal to twice the difference between the Drive checks. The predator is dealt +2 damage (a vehicle can ignore this damage if it currently has a Booster activated; see page 167).

SHORTCUT

Shortcuts can be helpful in catching up with prey, especially in close quarters, where the prey cannot see what the predator is doing. Unfortunately, this generally means that the predator has reduced its line of sight as well, which can result in a nasty spill.

Lead: Any distance.

Speed: The chase speed is reduced by 15 mph.

Success: The lead is reduced by a number of lengths equal to twice the difference between Drive checks. The predator must make a crash check during Step 6.

PREY MANOEUVRES

Each round the prey should write his or her manoeuvre down on a piece of paper and keep it secret. All prey manoeuvres are geared towards escaping the predator.

BARNSTORM (FINISHING)

“Barnstorming” is usually associated with planes, but any vehicle may attempt it. A car can storm a shopping mall, or a boat can storm the wreckage of an oil tanker.

Lead: 25 lengths or more.

Success: The prey wins the chase, barrelling through a cluttered area, throwing the predator if its trail in the chaos. The prey’s vehicle is dealt 3d6 damage. Both predator and prey must make crash checks during Step 6.

BOOTLEGGER STUNT

The prey brakes and turns hard to one side, suddenly changing direction. This can suddenly increase the prey’s lead.

Lead: 10 lengths or less.

Speed: The chase speed is reduced by 15 mph.

Success: The lead is increased by twice the difference between Drive checks, in lengths. The prey must make a crash check.

HAIRPIN TURN (FINISHING)

Hairpin Turn forces the predator down an erratic path as both mecha speed around tight bends and whip around blind curves until one falls out of the race. Hairpin turns tend to be longer and far sharper than those taken with Zig-Zag, resulting in a much greater chance of crashing. Lead: 20 lengths or more.

Speed: The chase speed is reduced by 25 mph.

Success: The prey wins the chase, taking a turn the predator cannot manage. Both the predator and prey must make crash checks during Step 6

.LURE

In many ways, the prey controls the direction of the chase, and can lead the predator into all kinds of foolish situations. Lead: Any distance.

Success: The lead is increased by one and the predator is required to make a crash check with a DC determined by the chase setting and increased by the difference between the Drive checks. The prey is also required to make a crash check this round (base DC of the chase setting).

Special: By beating the predator’s Drive check by five or more, the prey may choose to reduce both the predator and prey’s crash check DCs by five to shift the terrain by one step at the end of the round (open or tight becomes close and vice versa).

Furthermore, if the prey beats the predator’s Drive check by 10 or more using this manoeuvre, he or she may reverse the vehicles’ positions, becoming the predator until the end of the current round. The prey may attack the predator with forwardfiring weapons during Step 5.

PULL AHEAD

This is the basic prey manoeuvre, attempting to get as far ahead of the pursuit as possible.

Lead: Any distance.

Speed: Increase the chase speed by 10 mph.

Success: The prey’s lead is increased by a number of lengths equal to the difference between the Drive checks.

SET UP (MECHA ONLY)

Instead of running, the prey leads the predator on a merry chase, usually while exchanging fire.

Lead: 10 lengths or less.

Success: The lead is increased by one and the driver and all passengers in the prey mecha gain half the difference between the Drive checks (round down) as a bonus to all their attack rolls targeting the predator.

STUNT (FINISHING)

Stunts are incredible feats of skill, such as leaping a car across a rising toll bridge or ducking a giant robot between the blades of a huge turbine. This sort of manoeuvre is usually just short of suicidal, and only the most talented, foolhardy, or desperate try such a “perfect” escape. Lead: 20 lengths or more.

Success: The prey wins the chase, performing a stunt the predator just can’t manage. If the prey’s Drive check exceeds the predators by at least five, the predator must make a crash check in Step 6.

VANISH (FINISHING)

In a display of driving virtuosity and pure velocity, the prey leaves all pursuit behind, choking on dust.

Lead: 30 lengths.

Speed: Increase the chase speed by 20 mph.

Success: The prey wins the chase.

ZIG-ZAG

Zig-Zag involves purposefully clipping neighbouring obstacles, terrain and even other mecha in an attempt to direct them into the predator’s path, slowing him or her down. Unfortunately, this increases the chance that one of the prey’s “clips” may become a collision. Lead: Any distance.

Success: The lead is increased by a number of lengths equal to twice the difference between the Drive checks. The prey must make a crash check during Step 6.

STEP 2: DRIVE CHECKS

The mecha operators reveal their manoeuvres. Determine any changes to the chase speed this round as a result of manoeuvres. Each mecha operator makes an opposed Drive check (or other appropriate Skill check such as Ride or Swim; an opposed Dexterity check can be made if on foot), applying the following additional modifiers:

• The mecha’s Manoeuvre rating.

• Any speed bonuses gained from the terrain.

• Modifiers from Table A-1: Chase Manoeuvres.

• Modifiers from appropriate Feats.

• Modifiers due to one or other mecha being in a damaged Condition (see Step 6).

If one mecha operator succeeds, the effects of his or her manoeuvre are applied during Step 3. If neither mecha succeeds or the opposed roll results in a tie, the effects of neither manoeuvre are applied, and the chase continues without any effect from the manoeuvre other than speed changes. If both mecha operators succeed, the effects of the manoeuvre taken by the operator with the highest check result are applied during

Step 3. CHASE MANOEUVRE MODIFIERS

Find the predator manoeuvre across the top of Table A-1 and the prey manoeuvre along the side. Cross reference to find the modifier for each mecha this round. The number before the slash is applied to the predator’s Drive check, while the number after the slash is applied to the prey’s Drive check.

Manoeuvre

This adds to checks made to manoeuvre the mecha. It is based on how agile and quick to accelerate or turn the mecha is.

The Manoeuvre statistic starts at +8 if fine, +4 if diminutive, +2 if tiny, +1 if small, 0 if medium, -1 if large, -2 if huge, -4 if gargantuan, or -8 if colossal. For every every step in manueverability beyond Poor add +2.

TABLE A-1: CHASE MANOEUVRE MODIFIERS
	Box In	Crowd	Cut Off	Gunt It	Herd	Jockey	Ram	Redline	Shortcut
Haripin Turn	-	-	-	+0/-4	-	-	-	-2/+0	+0/-4
Lure	+0/-4	-4/+0	+0/-4	-2/+0	-2/+0	-	+0/-2	+0/-2	+0/-6
Pull Ahead	-6/+0	+0/-4	-2/+0	-	-6/+0	-2/+0	-2/+0	+0/-4	+0/-4
Set Up	-2/+0	-4/+0	+0/-4	+0/-4	+0/-2	-2/+0	+0/-4	-	-4/+0
Stunt	-	-	-	-2/+0	-	-	-	-4/+0	+0/-2
Vanish	-	-	-	+0/-4	-	-	-	+0/-6	-4/+0
Zig-Zag	-2/+0	+0/-6	-2/+0	-6/+0	+0/-6	+0/-2	-4/+0	-2/+0	-

 

STEP THREE: RESOLUTION

The effects of the winner’s manoeuvre are applied to the chase. Remember that the lead cannot, at any time, be less than zero or over 30 lengths. If the winner chose a finishing manoeuvre, then the chase ends after the remainder of this round’s steps are completed. If not, the chase will continue with a new round following Step 6, unless the chase ends because of obstacles, crash checks, or combat.

STEP FOUR: OBSTACLES

The GM may wish to throw in some obstacles to add to the action. These can range from an overturned petrol tanker and sections of heavy road construction (ground chases) to overhead power cables or a firework display (air chases) to a low bridge or coral reef (water chases) to a locked door or concealed rabbit-hole (foot chases). An obstacle typically requires either a Reflex save or Drive check against the obstacle’s DC. If the check fails, the mecha operator must make a crash check during Step 6.

The prey makes his or her save or Drive check before the predator does. The base DC for avoiding an obstacle is determined by the terrain, but the GM may alter the DC by up to +/-2, depending on the size and complexity of the challenge.

Obstacles are intended as spice, not the focus of chases, and can be ignored completely by the GM. If the predator and prey get stuck in a rut, the GM should use obstacles to shake things up. If the mecha are keeping things dynamic, the GM should reserve obstacles for a more effective time. The frequency that obstacles crop up is based on the local terrain.

STEP FIVE: OTHER ACTIONS

Whether the chase has ended due to a finishing manoeuvre or not, all passengers are allowed one full action or a standard action and a move action. Any mecha operator may take one standard action or move action at the cost of a -4 penalty to his or her next Drive check. In most ways, combat during a chase follows the basic combat rules, with a few significant differences.

ACTIONS DURING CHASES

During chases, creatures act in Initiative order as usual, but many actions are restricted or illogical.

Initiative: Initiative works normally during chases.

Attack: A passenger in a moving mecha has a -4 penalty to his or her attack rolls. The operator of a mecha has a -8 penalty to his or her attack rolls. Furthermore, the operator and all passengers take an additional -2 penalty for every full 50 mph their mecha is travelling. Melee attacks can only be made if the prey’s lead is 0 and/or or the attacker is in or on the same vehicle as his or her target.

Movement: Movement actions may be taken, but a Balance check is needed in most cases. A Jump check is required to leap between two moving mecha. Finally, if a character falls from a moving vehicle, he or she suffers +2 damage per 10 mph of the vehicle’s movement, but may make a Jump or Tumble check (DC 20, +2 for every full 25 mph the vehicle was travelling when the crash occurred) to halve the damage and convert it to stun damage.

Other: Other actions may or may not be possible, at the GM’s discretion. In general, only Skills and Feats that don’t require movement remain unaffected.

STEP SIX: DAMAGE AND CRASHES

The last step in every chase round is to apply damage (if any) to each mecha, and see if they have collided with the environment (or each other).

CONDITION SUMMARIES

There are four possible conditions that participants in a chase can be in.

Mecha Okay: The mecha is only lightly damaged. There are no modifiers to the Drive check (or other appropriate Skill check such as Ride or Swim; a Dexterity check can be made if on foot).

Mecha Disabled: A mecha which has been reduced to disabled. Its Manoeuverability is reduced one step. The character must make an immediate crash check, with the DC increased by +5.

Mecha Destroyed : A mecha or creature that has been reduced to destroyed either stalls and comes to a halt, or topples over (if a walking rather than wheeled mecha). The driver must make an immediate crash check, with the DC increased by +10. As well as a pilot or drive check against 10 + the number of hits the vehichle has taken.

Mecha Destroyed Permanent : A mecha pilot has failed his pilot check to stablize the mechs reactor. It rolls, skids, plummets, or stumbles to a halt, then explodes, completely useless for any purpose (although it may now count as one or more Obstacles at the GM’s discretion). Occupants of the mecha when it is destroyed are damaged as though they had jumped out of the vehicle at the speed it was moving before it crashed; a successful Jump or Tumble check in this case means they jump free.

CRASH CHECKS

Crash checks should be made in three instances:

Table A-2:Crash Checks
Circumstance	DC
Open Terrain	15
Close Terrain	20
Tight Terrain	25
Every full 25 mph of speed	+2
Each check required in a round beyond the first	+5

• when the mecha operator fails a Drive check to avoid an obstacle.

• when a successful manoeuvre calls for one.

• when the mecha takes a hit.

A crash check is a Drive check (or other appropriate Skill check such as Ride or Swim), but a mecha operator makes only one such check each round. The base DC for a crash check is based on the terrain for the chase. If a mecha operator is required to make multiple crash checks in a round, he or she instead makes a single check, adding 5 to the DC for each additional crash check called for during the round.Whenever a mecha operator fails a crash check, his or her mecha collides with the environment (or the other mecha, if the successful manoeuvre calls for it). Damage to each vehicle (and occupant) equals +2 for every 10 mph of vehicle speed, +1 point for every point by which the mecha operator failed his or her crash check (crashes at high speeds are often instantly fatal). Each occupant of the mecha can make a Jump or Tumble check (DC equal to the DC of the failed crash check) to jump free of the mecha, reducing the damage by half and converting it to stun damage.

CONVERSIONS FOR HIGHER OR LOWER SPEEDS

The chase rules reflect a typical mecha or modern vehicle game, where chases typically occur at around 80 to 120 mph. For a chase involving solely characters on foot, who do not have the Speed Attribute, when a manoeuvre calls for speed to change, divide all mile-per-hourfigures by 5. For faster-moving mecha chases, up to and including spacecraft, increase all mph figures by a factor of 2 or more. The suggested amounts are x2 for chases taking place at around 200-400 mph, x5 for chases taking place at between 400 and 1,000 mph, and x10 for chases taking place at over 1,000 mph.

Dramatic space flight should convert mph figures to percentage of light speed for chases, so a manoeuvre that would usually increase speed by 10 mph increases it by 10% of the speed of light (or 0.1 C) instead. Realistic or solar sail space flight games rarely use the chase rules, since the acceleration of the vehicles will likely be far too low in comparison to the distances between predator and prey — whichever vehicle starts to accelerate before the other will almost always win any “chase.” FTL games may convert the chase rules as appropriate to the typical speeds available.