A character's jumping ability may be of
critical importance in an AD&D® game
adventure, yet there are no official rules
covering such an action. In developing a
system to fill this gap, there are 3 major
considerations. The 1st and most important
one is that such a system should be
simple, especially if it is to be used frequently.
The 2nd is that player and
characters should not be presented with too
many absurdities. If in the game ordinary
humans can only jump 4 feet (a little more
than a long stride), or if on the other hand it
is unexceptional for a character to jump
twice his own height, then the facade of
realism is broken. Players will more likely
object to peculiarities in the rules for jumping
than in the rules for something less
familiar, such as medieval combat, or something
entirely fantastic, such as magick. The
3rd thing to consider is that while realism
can be important, fantastic feats are a necessary
part of a game that imitates heroic
fantasy. Characters with exceptional ability
and training should be capable of leaps that
would be phenomenal in the real world.
The system described here takes into account
these factors and attempts to arrive at
a reasonable compromise between them.

The core of this system is the "jump
number," which describes the maximum
distance in feet that a character can cover or
clear in a jump. It is doubled for a long
jump (with a running start), halved for a
high jump or a backwards jump, and remains
the same for a standing broad jump.
A high jump may be the hurdling of a barrier,
or the grasping of a target the same
distance above a character's head, or arrival
atop a ledge or barrier. The long jumps are
self-explanatory. The basic jump number
for a character is determined using the 3
tables on the next page.

It is assumed that the character, being a
heroic adventurer and, having decided to
attempt a jump, does not lose confidence at
the last second. It is also assumed that the
critical second. It is also assumed that the
character is in good enough condition that
surplus body weight is not a factor. The sex
of the character is not considered either;
female adventurers are presumed to have
physiques as well suited to running and
jumping as those of their male counterparts.
Adjustments might be made for nonadventuring
females, but this is not in the
spirit of the AD&D®game. If it were, males
and females would have slightly different
running speeds as well. Consider any limitations
due to a character's sex to end with
the restrictions on maximum strength given
in the Players Handbook.

The racial adjustments given are for
stature and build, and for natural skill (or
lack of it) in jumps and leaps. Smaller individuals
are stronger pound for pound than
larger ones, so they are not so limited in
jumping ability as might be thought.
Gnomes, for instance, are as strong as
humans even though they weigh a good deal
less, and so have only a -1 adjustment to
their jump number despite their short legs.

Adjustments by character class are for
facility with leaps according to training.
Multi-classed characters may use their more
favorable adjustment, if applicable.

In determining a character's combined
strength and dexterity, each class of percentile
strength counts as another point of
strength -- for this calculation only. Thus,
18/01 to 18/50 strength is treated as 19,
18/00 is treated as 23, and hill giant
strength (19) is counted as 24. Extraordinary
totals can be extrapolated from the
table, following the obvious trend of the
numbers.

A character?s basic jump number according
to strength, dexterity, race, and background
will seldom if ever change in the
course of a campaign. It should be recorded
with the primary statistics of the character.
This number may of course be modified
according to the circumstances of a jump,
as shown below:
 

Surface being jumped from or to is:	-
concealed	-1/2
slippery	-1
uneven	-1
unstable	-2
Encumbrance:	-
each hand occupied	-1
per 100 gp carried	-1/2
Runup:	-
each 1" faster/slower than 12"	+/-1/2
each 5' of runup missing	-1/2
Elevation of target surface compared to takeoff surface:	-
Abovc:	-1/2 for the first 1/2' of elevation, doubled for each further half-foot (i.e. -1/2, -1, -2, -4, -8, -16, etc.)
Below:	+1 for each of the first 10 feet of difference, +1/2 for each of the next 10, with no further modification thereafter.

Obviously, some of the above modifiers
do not apply in all cases. The runup is only
important in a running long jump, and the
height of the target surface is already taken
into account or is unimportant in a high
jump. When they do apply, situational
modifiers are cumulative. For instance, a
jump from an uneven, slippery, unstable
surface with 400 gp in encumbrance, some
of which is in each hand, is made at a penalty
of -8.

Modifications for surface conditions
apply to both takeoff and landing points, so
that for instance a long jump from an unstable
surface to another unstable surface is at
-4. In some kinds of high jumps (hurdling,
for instance) the condition of the landing
surface is unimportant. A concealed surface
is one blanketed by something like snow or
vegetation so that its true nature is unknown
to the jumper. An uneven surface
can be anything from heavily furrowed
ground to an area strewn with boulders.
Slippery and unstable surfaces are self-explanatory.
These factors might be doubled
for extraordinarily adverse conditions.

The runup required for a running long
jump is equal to twice the distance to be
covered in the jump; a 20-foot-long jump
requires a minimum 40-foot runup.  Since a
character's movement rate may change in
the course of an expedition, and since it is
not a factor in most kinds of jumps, it is not
considered in the calculation of the basic
jump number.  It may be useful, however, to
record the usual adjustment for a character.
In practice, there is a bonus or penalty of 1'
(raising or lowering the character's maximum
jumping distance accordingly) for
each 1" of movement rate faster |or| slower
than 12" whenever a running long jump is
attempted.  Charging is not usually considered,
since the jumper is presumed to be
moving at maximum SPEED on takeoff.
However, a jump that finishes on |or|  directly
before an opponent is considered to be da
charge for determination of effective AC,
attack priorityt, and damage.

If, when leaping to a target lower than
the takeoff point, a character descends more
than 10 feet, he will take normal falling
damage for that extra distance. A leap from
the top of a 30-foot-high cliff to some point
at or beyond its base will mean damage to
the jumper as if from a 20-foot fall. This
mitigation of damage applies only to intentional
descents; if as a result of a failed
jump someone falls into a pit or a chasm,
damage is calculated in the usual way.

Most jumps can be defined as one of the
basic types, but in important situations in
which a distance and a height must be
cleared together, treat the jump as a long
jump with adjustments for target height. If
the barrier to be cleared is at the start or
end of the jump, the character must have a
jump number sufficient to land on a surface
one-half foot higher than the barrier (the
character wants to clear it, not land on it).
If the barrier is near the middle of the
jump, treat the jump as an attempt to land
on a target surface half that high, plus half a
foot. Thus, a 2-foot-high barrier at the start
or the end of a jump will mean that it is 8
points more difficult (equivalent to trying to
reach a 2½-foot-high target surface). If this
same 2-foot-high barrier is in the middle of
a jump, the jump is made at a penalty of -2
(equivalent to trying to reach a 1½ foothigh
target surface).

As mentioned before, the adjusted jump
number for a character describes the distance
that the character will certainly succeed
in clearing. (Remember that the jump
number is doubled to get the maximum
distance for a running long jump, and
halved to get the maximum height for a
high jump.) There is a chance of extending
a leap beyond the usual maximum, but this
chance decreases rapidly with the required
increase in jump number, as shown in the
table below:
 

Extra jump no.	Chance of success	Recovery timee
0	100%	none
1/2	80%	2 segments
1	30%	4 segments
1 1/2	10%	8 segments
2	2%	1 round

Trying to extend jump not only increases
the chance of failure but also introduces
the concept of recovery time. Because
the landing is awkward, or because the
character must rest after overextending
himself, the jumper is unable to take any
action for a certain length of time after
making an extraordinary leap. For example,
a 3-foot extension of a running long
jump has a 90% chance of failing and, if
successful, prevents the jumper from taking
any action for 8 segments thereafter. If a
character fails an extension, he still covers
the minimum distance specified by his
normal adjusted jump number, and may
even make a lesser extension, but recovery
time is still as specified in the above table
for the jump that was originally attempted.
If the character in the above example fails
the 3-foot extension with a dice roll of more
than 10 but less than 31, then he has successfully
made a 2-foot extension instead,
but recovery time is still 8 segments.

This system is hardly an exact simulation
of real-life jumps, and any amateur athlete
will certainly find faults in it. However, it is
designed to be compatible with the AD&D®
game system, and is easily as realistic as the
combat or movement rules. As a final note,
remember that all of the distances given are
for less than ideal conditions. If players join
in a competition, with sand pits, practice
runs, and an opportunity for premeditation,
add another point to every individual?s
jump number.

How the system works
Example 1: Jan Zweihander, a human
fighter, is chasing a wily halfling thief
through the streets of the canal-town of
Vence. He has nearly caught up when the
thief reaches an 11-foot-wide canal and
decides to jump it. Jan follows. The halfling
has a basic jump number of 7 (strength 8,
dexterity 15, race and class adjustments
canceling out). She is moving at 9?, and
carrying a dagger at her belt and Jan?s
money (100 gp) in her pack, for a total of
130 gp encumbrance. Her modified jump
number is 5, so in a running jump she has
an 80% chance of making the distance. She
does, just clearing the canal and reaching
the opposite bank. Jan?s basic jump number
is also 7 (strength 15, dexterity 8), but he is
wearing a pack with 75 gp in encumbrance
worth of food and equipment, and is carrying
his two-handed sword (all of value he
has left) in his right hand. His modified
jump number is 4½; he has a 30% chance
of making the necessary extension of 1.
Unfortunately he fails miserably, falls a full
two feet short of his target, and lands in the
smelly canal-water. By the time he climbs
out, the halfling and his money have long
since disappeared.
 

Example 2: Calliran Copperhair, an elven
fighter-thief, is being pursued across a
pasture by an angry bull. He plans to get a
4½-foot-high fence between himself and the
bull before he is run down. Calliran?s
strength is 12 and his dexterity is 17. With
modifications for his race and his thief
training, his basic jump number is 10. He is
carrying a pack with equipment in it
amounting to 30 gp encumbrance, and he
has a dagger at his belt. He dropped his
longsword when he saw the jump he would
have to make, so with a total of less than
100 gp in encumbrance he is not hampered
at all. The grass of the pasture is wet with
dew (-1 adjustment for the slippery surface),
so his modified jump number is 9. Calliran
sails over the fence, just barely, and will live
to retrieve his sword.
 

Example 3: Shara, a half-elven druid, is
not far ahead of a horde of angry orcs when
she comes to a cliff over the ocean. Looking
down, she can see that the tide is in, but it
is 50 feet down to the water and there are
rocks (indicated by heavy surf) for some
thirty feet out to sea. She throws most of
her equipment as far seaward as possible,
hoping to find it when she reaches the bottom
of the cliff. She stops to cast her water
breathing spell on herself. Then she backs
up a good hundred feet (she is going to try
to jump as far as possible), and takes a
running leap from the cliff into the waves
below, just ahead of a flight of orcish arrows.
Her total of strength and dexterity is
20, so her basic jump number is 6½ plus ½
for her race. The jump number is increased
by +1 for each foot of the first 10 feet of her
descent, and by +½ for each foot of the
second 10 feet, for a +15 adjustment in all.
The top of the cliff is rocky (-1 for the uneven
surface). Lastly, she is wearing her
leather armor, and carrying in her pack 200
gp encumbrance in materials too valuable
to risk losing. Her total of 370 gp encumbrance
(200 in her pack, plus 150 for the
armor and 20 for the pack) means a penalty
of -2, after rounding 370 up to 400 (the
nearest 100 gp increment). With a final
adjusted jump number of 19, she easily
clears the rocks below and lands hard on the
surface of the water 38 feet away from the
shore. She tried to extend her leap as much
as possible, but failed entirely with a percentile
roll of 87. Fortunately, her jump was
good enough anyway. If she had landed on
the rocks she would have taken falling damage
for an intentional descent, but she is
fortunate enough to land in 20 feet of water.
She will be able to swim underwater to
some sheltered spot out of range while the
orcs are still cursing.
 

LETTERS

Issue #93: The first sentence of the third paragraph
in "Short hope and big drops" (p. 21) is
followed by an unintelligible statement. Delete
the words "It is also assumed at the critical
second."
 

Jump adjustment
-
Dear Dragon,
I have a question about "Short hops and big
drops" (issue #93). In the example where Jan
Zweihander is chasing a halfling thief, wouldn't
the halfling's extra jump number be 1, because
his modified jump number is 5, changed to 10
because of a running long jump, and 10 subtracted
from 11 is 1. So he would have a 30%
chance of jumping instead of 80%. Would you
explain this a little better, please?
 

Travis Boelter
New Ulm, Minn.
(Dragon #96)
 

Yes, it should be explained a little better. The
computation in the example is correct, because
the "double credit" for a running long jump was
accounted for by dividing the distance of the 11-
foot jump in half. The halfling's chance of success
was calculated as if she were attempting a 5½-
foot horizontal jump with no running start. That
distance is only ½ higher than her modified jump
number of 5, which is why (according to the table
on page 22) her chance of success is 80%. Dividing
the distance in half accomplishes the same
thing as doubling the character's jump number
for a running long jump. The division step was
done "automatically" in the text of the article,
not explained when it was performed, so we can?t
blame anyone for not quite understanding how
the example worked.

-- KM
(Dragon #96)
 
 

A jump too far
Dear Dragon,
I found the article "Short hops and big drops"
(#93) very useful. However, it does not mix with
the Unearthed Arcana version of jumping. The
book says a thief-acrobat with 15 strength and 16
dexterity can make a running broad jump of 9
feet at sixth level, and any other character can
broad jump 8 feet. But in the article, a character
with combined strength and dexterity of 31 would
have a basic jump number of 9, which would be
doubled to 18 feet for a running broad jump.
Could you clarify this?
    Peter Colucci
    Alta Loma, Calif.
    (Dragon #105)

You've clarified it very well, Peter. The two
systems are drastically different in most respects
-- so different that they can't be used side-by-side
in a campaign without seriously weakening the
thief-acrobat split class (Imagine a world where
anyone with a combined STR and DEX of
14 or higher could jump better than a 6th-level
thief-acrobat.)

If thief-acrobats exist in your campaign but
you like the mechanisms of the "Short hops"
system and you think everyone else ought to have
a chance of being able to jump, then you'll have
to do some extensive fiddling with the way a
character?s jump number is determined. I?d start
by reducing the basic jump number to two-thirds
of its present value (and I?d make the ?Combined
strength and dexterity? column top out at 36-37;
beyond that, you don?t get any better). Now a
non-thief-acrobat with a combined strength and
dexterity of 31 has an unadjusted jump number
of 6; under non-hazardous conditions, he can
clear 12 feet in a running broad jump. But this
character is near the limit of his physical ability;
he has only a 30% chance of being able to extend
the jump to 14 feet, and he?ll never get any better
at jumping than he is already. The thief-acrobat,
on the other hand, has a 50% chance of extending
his jump to 13 feet ? and he?s only at the low
end of the scale; as he gains experience, he?ll get
even better at jumping.

Reducing jump numbers by one-third means
that a character with an average score (21) in
combined strength and dexterity has a jump
number of 4, and can clear 8 feet in a running
broad jump ? the same distance given in Arcana
for a non-thief-acrobat character.

Although it seems inappropriate to use a
character class that specializes in jumping plus a
separate jumping system for everyone else, you
may be able to find a way for them to work
together. The answer lies in toning down the
average guy?s ability to jump, not in improving
the figures for the thief-acrobat. -- KM