Chase Rules

Source: DMG 2 Pg 57

A dramatic chase has become a classic staple of the action
and fantasy genres. They give fast characters a chance to
show off, and provide uncertainty and tension as players
scramble to pursue an important villain.
Chases can be resolved fairly easily while still maintaining
a high level of drama. The fi rst thing to consider is
speed. If the pursuer and her quarry have the same speed,
the pursuing character needs to gain speed advantages in
the course of the pursuit to catch her opponent. The one
being chased, meanwhile, has the opportunity to introduce
obstacles to slow down his pursuer.
If the characters have different speeds, the matter is more
easily settled. Each round, compare the speeds of the two
involved in the chase. If the difference in speed is in favor
of the pursuer, she closes the gap between the two by that difference each round. If the speed difference is in favor of
the fl eeing character, the gap widens by that amount. Most
chases don’t allow the participants to use the run action (×4
speed), and consist only of double move actions.
Pits and Gaps
In a chase, pits and gaps can be excellent obstacles. Speed
being equal, the character with the better Jump check
modifier is likely to have an advantage during a chase
that involves leaping over a gap. A character who fails by
less than 5 on a Jump check to clear a gap can attempt a
DC 15 Refl ex save to grab the lip on the far edge. Pulling
up from such an edge requires a move action and a DC
15 Climb check.
In a given round during a chase, there’s a 10% chance that
the terrain contains debris a creature being chased can
scatter to slow down his pursuer. In urban environments,
the chance increases to 30%. The chased character can
make a DC 10 Strength check as a free action to tip debris
over behind him as he runs. Success on this check scatters
debris over a 10-foot-square area in the path of the pursuer,
making the area the equivalent of dense rubble. Diffi cult
terrain requires a character to spend 2 squares of movement
(per square) to enter. Failure means the chased character
not only fails to knock the debris over but spends a move
action trying to push the pile over and then recovering.
If you wish, you could provide a chased character with
larger piles of debris to spill. For each additional 10-footsquare
section the character tries to turn into diffi cult terrain,
the DC of the Strength check increases by 5. The character
doesn’t need to try to tip over the entire pile of debris, and
can choose to knock over as much or little as he likes. Failure
on these higher DC checks has the same result.
Some kinds of debris might not need to be toppled
over. Perhaps oil or another slippery surface covers an area
through which the chase proceeds. Maybe the creature
being chased runs into a crowd or through a building.
Different situations might call for different adjustments or
skill checks. As a general rule, if debris is of the sort that
impedes a character’s progress, it can be treated as dense
rubble. Even a crowd could be treated as rubble if keeping
a scene moving is more important than dealing with a
crowd’s reaction to being pushed around. If debris is of the
sort that causes unsure footing, use a Balance check.
Running up inclines should be common in chases. Whether
the characters involved sprint up peaked roofs, up stairs
to higher elevations, or up a hill, an incline can make for
an interesting chase element.
As described under Hills Terrain, page 89 of the Dungeon
Master’s Guide, gradual slopes have no effect on movement.
Steep slopes, however, require characters to spend 2 squares
of movement to enter each square of steep slope. A slope
covered with debris is even more diffi cult to deal with;
characters entering a debris-fi lled square on a slope must
spend 3 squares of movement.
Types of Chases
When planning a chase scene, consider setting it where
you can add unique terrain elements to make the event
memorable. A chase through a cramped sewer, where
PCs need to squeeze to pursue their prey, is a perfect
example. Moving into a narrow space takes 2 squares of
movement, and creatures can squeeze into an area half
as wide as they are. Combine that with a foot (or more)
of water and the occasional passage with a low ceiling,
and you have a dank, miserable chase your characters
won’t forget.
Likewise, consider a chase across a series of mountain
glaciers. Chasms open up beneath the characters and
their prey’s (or pursuers’) feet on occasion, requiring Jump
checks or DC 15 Refl ex saves to avoid dropping hundreds
of feet into an icy gap. The terrain is also slick with ice in
places, requiring DC 10 or higher Balance checks from
involved parties to keep their footing.
Consider the following situations or environments in
which you can run your own chase scene:
• Across a rooftop or series of rooftops
• Through a crowded marketplace
• Through a series of forest paths
• Across a series of sand dunes
• Through a labyrinth of urban alleyways
Movement in a Crowd
People in crowds are packed together tightly, sometimes
shoulder to shoulder. As a general rule, a single 5-foot square
occupied by a crowd of Medium creatures contains three
Medium creatures. These cramped conditions make moving
in a crowd diffi cult. It takes 2 squares of movement to move
through a square occupied by a crowd. The crowd provides
cover for anyone who does so, enabling a Hide check and
providing a bonus to Armor Class and on Refl ex saves.
A character who ends his movement in a stationary
crowd square fi nds it diffi cult to do anything but move
with the crowd. He takes a –2 penalty on attack rolls,
Refl ex saving throws, and all skill checks that are affected
by armor check penalties, and he loses his Dexterity bonus
to Armor Class. Being in a stationary crowd square counts
as vigorous motion for the purposes of spellcasting (requiring
a DC 10 Concentration check).
A character who ends his movement in a crowd square
that moved in the last round faces an additional danger.
He can take a full-round action to stand his ground, he
can take a full-round action to move with the crowd, or
he can try to resist the crowd’s motion. A character who
tries to resist a crowd in this manner must make a DC
15 Refl ex save. Success indicates that he takes the same
penalties as for being in a stationary crowd, except that
the action constitutes violent motion (requiring a DC 15
Concentration check to cast spells). Failure indicates that
the PC loses all actions for the round and is subjected to a
trip attack. The crowd has a +8 bonus on the opposed attack
roll to resolve the trip attack. If the character is knocked
prone, he is trampled for 2d6 points of damage.

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