Tuesday, October 09, 2012

Character Fatigue - Movement & Encumbrance

In the past article I made a quick review of heart rate and exercise and how this works to setting the base for determining character fatigue.  In this article I'll show the basics of the movement rules in Era and how fatigue fits in.

I'll start with a human load capacity of 10 kg called the base load.  Any character carrying less than the base load is said to be "unloaded".  A character that carries over the base load is said to be loaded up to 1.5 times the base load and is said to be encumbered if over 1.5 the base load (loaded weight).

The following table shows the amount of load a character can carry based on the strength.

Strength to Load Table

STR
Load Modifier
Unloaded
(up to)
Loaded
(up to)
Encumbered
(up to)
3-6
0.5
5Kg
10Kg
15Kg
7
0.75
7.5Kg
15Kg
22.5Kg
8
0.75
7.5Kg
15Kg
22.5Kg
9-12
1
10Kg
20Kg
30Kg
13
1.5
15Kg
30Kg
45Kg
14
1.5
15Kg
30Kg
45Kg
15
2
20Kg
40Kg
60Kg
16
4
40Kg
80Kg
120Kg
17
10
100Kg
200Kg
300Kg
18
20
200Kg
400Kg
600Kg


Then I set four different speeds which will correspond to the different levels of exercise explained in the previous article (warm up, fitness, cardio and hardcore).  The speed values are given below.

Base Speed

Walk (Base move ) : 5Km/h               14m/round      40”/round
Jog                        :  7.5Km/h            21m/round      60”/round
Run                       :  10Km/h             28m/round      80”/round
Sprint                   :   15Km/h             35m/round    120”/round
round = 10 seconds

So how much does a character tire while running?  Well the interesting thing is that characters will tire the same under the same load and same exercise.  So a character that jogs will jog at 60 - 70% max heart rate when unloaded.  A character with higher strength will be able to carry more and jog a bit faster than others, but overall the load to the cardiovascular system is the same.  This leads us to the simplified fatigue, load and speed table below.  On the first row we see the unloaded performance.  One you would see from a 10K runner or a marathoner.  Walk causes no wear at all and unless done for prolonged periods it would cause no significant fatigue.  Jogging causes one half of the Fatigue Recovery (FR) to be used up.  Fatigue recovery is nothing more than the constitution or endurance attribute of the character.  As the character begins to run the body can no longer replenish oxygen at the same rate and wear equals fatigue recovery.  The character is now in the cardio heart beat range.  As the character pushes the envelope and sprints he or she reaches the anaerobic range of VO2max and the body begins to quickly lose stored energy.  After a few seconds or a minute or two of sprinting the character will wear out.

If we load the character down the values move one to the left.  Walking now becomes a fitness and fat burning exercise.  Jogging is now cardio and running which was once cardio is now hardcore VO2max exercise.  Running wears the character out just like a sprint did before, but does so at an overall lower movement speed.  To reach spring speeds the character must push even harder wearing the body out quicker.  Fatigue wears out at three times the recovery rate.

Finally if the character is encumbered then even walking is a cardio activity.  Jogging is now extreme VO2max activity and running and sprinting are near superhuman efforts.  Under these encumbrance loads walking requires periodic rest to recover energy and oxygen to the muscles.  Marching for over half an hour is an strenuous task even for the well trained.

Fatigue, Load and Speed Table

Load
Walk
Jog
Run
Sprint
Unloaded
0
½ FR
1xFR
2xFR
Loaded
½ x FR
1xFR
2xFR
3xFR
Encumbered
1xFR
2xFR
3xFR
4xFR

As you can see using cardiovascular load as a reference it is easy to factor in fatigue without a lot of bean counting in the process.  Just base yourself off the encumbrance load the character can carry and assume all speeds are the same for all characters.  A consideration can be added for special training or conditioning or higher constitution characters can have a bonus in speed, but this should not be too great and would be better based on age.  For example I can run a 10k in 45 to 48 minutes while the winner does it in 30 minutes. That's a 35% drop in time at the cost of extensive training.  So getting too specific on actual speed beyond the ballpark values given here might make little sense unless the character enjoys extensive training.

In the next article I'll explain how all this fits into the fast actions and combat rules.  The objective of the rules is to create a way to represent what a character can do in a round without being bound by rules like 2 attacks per round, or one spell per round.  Also to factor in weapon and armor effect on fatigue so players can look into more interesting characters that still make combat sense.  Instead of the classic biggest armor and biggest sword possible.  It also looks at integrating movement as an integral part of combat, not the move and attack, but rather attack on the move and choose different ways to move, speeds and loads.  Should I jettison my backpack prior to combat.  Move in with shield and sword or buckler and spear?  Overall look for different gear layouts that give the character and edge in combat.

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