Falling
Falling is one of the most underrated and misunderstood forms of movement. It has a number of advantages over more conventional modes of transportation, but also some well-known draw-backs. Oddly enough, terminal velocity is not the problem; like anything exhilarating and addictive, it's giving it up rapidly that causes the most grief.
Terminal Velocity
Terminal velocity is not a fatal speed - it's the fastest you can fall. Smaller creatures have lower terminal velocity; the critical size cut-off for terminal velocity being ‘terminal' is the common housecat. Experiments have shown that when a cat is dropped from beyond 100 feet, it will usually break its ankles on landing, but be otherwise unharmed. When falling from a height of 60 to 80 feet, the cat will have sped up and the funiculi (see below) will have not had time to slow its fall, so the cat usually dies; below 60 feet, the cat is usually travelling slowly enough to survive. Any larger animal, such as a small dog, usually dies on falling from above 50 feet, while rodents and other creatures smaller than a cat are essentially unharmed; they reach terminal velocity within a few feet, and can fall any greater distance safely.
As well as varying by the faller's size, terminal velocity is higher at greater altitudes. For humans, terminal velocity is around 180 feet/second at sea level, or 200 feet/second a mile up; for halflings it's a little less, while giants can obtain speeds in excess of 300 feet/second at high altitudes. Large constructions like flying boats have varying terminal velocity based on their hull shape and sail configuration, but they rarely fall as fast as a human.
The reason why there is a maximum falling speed is due to the funiculi in the air, which act as weak springs to slow down a faller. They have more effect the faster you are falling as the more funiculi you pass through, the more you are slowed. The variances in terminal velocity are also explained by funiculi: as the air grows thinner, there are less funiculi; and obviously smaller creatures need less force to slow them down.
Post-Terminal Velocity
Many birds are not built for steep dives, and would have their wings ripped off if they tried, but some birds that hunt large prey (fish, other birds, or small animals) have mastered the technique of flying downwards. These birds generally need to fold their wings back along their body, reducing their wing area, and control their movement with subtle twitches of their flight feathers. Sea birds often dive into the water from a height, usually at around 60mph, which is roughly the maximum speed that it is safe to hit the water - when diving any faster, the water will behave more like land on impact. Some raptors also use this approach to dive upon unsuspecting prey from a great height, and either knock it from the air or seize it in their talons. The peregrine falcon is the most extreme avian faller, capable of stooping from a height of twelve thousand feet, and hitting their victims at up to 220 mph. This speed is far greater than their level flight speed of 30mph, or even their "natural" terminal velocity of 80mph, and is reached by streamlining their shape and falling like an arrow. A few enterprising humans have experimented with speeding up their fall through plunging head or feet first, and have reached 300 ft/s (200mph); apparently travelling head-first is slightly faster, but can be disorienting at low altitude. This technique could be used to catch up to other fallers who have gained a head start, but please note that it will take some time (and hence distance) to match speeds with your fellow travellers, and that hitting another human at a relative speed of 80 mph can led to some discomfiture. One further point to remember is that at post-terminal velocity, any sudden uncontrolled movement can cause you to tumble haphazardly through the air, and it may take several seconds to regain your composure; this time may not be available at low altitudes.
Falling Damage
Rule of Thumb: A creature should take a maximum damage equal to their weight in pounds (including equipment), apart from any specific grievous injuries.
Rule of Thumb: Damage on impact is proportional to speed squared (minus a little absorbed by landing). Rather than taking (height/10)2 EN damage, taking (impact speed in ft/s /10)2 EN damage would be more appropriate. A deliberate jump could lower the damage by ~TMR. A comparison table is given below, using a simple approximation of 5 EN / 10 foot fallen (TMR has not been removed). This is simpler and more accurate than the current rules, and means that falling from vast heights will only be mildly fatal. Falling onto snow, water, etc can be calculated using 2 EN/ 10 foot or similar reductions; in these circumstances, maximum damage should also be reduced. Note that 1 foot/second = 1 TMR. Also, note that this table does not include the specific grievous injuries that are bound to occur when participating in this popular rough-and-tumble sport.
- Falling Damage
| Height | Impact speed | Rules damage | Simple damage | |
|---|---|---|---|---|
| 10' | 25 ft/s | 17mph | 1 | 5-TMR |
| 20' | 38 ft/s | 26mph | 4 | 10-TMR |
| 30' | 44 ft/s | 30mph | 9 | 15-TMR |
| 40' | 50 ft/s | 34mph | 16 | 20-TMR |
| 50' | 56 ft/s | 38mph | 25 | 25-TMR |
| 60' | 62 ft/s | 42mph | 36 | 30-TMR |
| 100' | 78 ft/s | 53mph | 100 | 50-TMR |
| 500' | 144 ft/s | 98mph | 2500 | 250-TMR |
| 1,000' | 168 ft/s | 115mph | 10000 | (weight in lbs) |
| 3,000' | 180 ft/s | 123mph | 90000 | (weight in lbs) |
Flying Damage
A remarkable number of adventurers hit solid vertical surfaces at high speed. While I've never understood why they do it, we can use the same guidelines as falling to determine their fate (note that you can't duck-and-roll when flying into a wall). Often a "slider", as these unfortunates are known, will slow slightly before hitting the wall and sliding down it, so you may not want to use their maximum velocity.
Rule of Thumb: Damage on impact is as per falling. Using miles per hour, this is roughly (mph/7)2 EN damage.
- Flying Damage
| Impact speed | Damage | |
|---|---|---|
| 20mph | 29 ft/s | 9 |
| 30mph | 44 ft/s | 19 |
| 36mph | 53 ft/s | 28 |
| 40mph | 59 ft/s | 34 |
| 50mph | 73 ft/s | 54 |
| 60mph | 88 ft/s | 77 |
| 100mph | 147 ft/s | 215 |
Time To Ground
Generally, the most important piece of information a free-faller will need is the time that they have until landing, known as Time To Ground or TTG. There are several critical altitude thresholds, and they are listed below, along with typical times taken for a human to reach sea level from each height, starting from stationary.
- Distance vs. Time from Stationary
| Height | Reason | Time to Ground | Max Speed | |
|---|---|---|---|---|
| 35' | Below this, adventurers just jump | 0:01.5 | 45 ft/s | 31mph |
| 60' | Typically lethal | 0:02 | 60 ft/s | 41mph |
| 100' | Time for one action | 0:02.5 | 75 ft/s | 51mph |
| 350' | Time for trigger or quickened cast | 0:05 | 130 ft/s | 89mph |
| 1,200' | Time for cast. Minimum safe flying height | 0:10 | 170 ft/s | 116mph |
| 5,280' | 1 mile. | 0:30 | 190 ft/s | 130mph |
| 10,000' | Max safe altitude without Aerial Affinity | 0:55 | 200 ft/s | 136mph |
| 20,000' | Max Summoned Cloud height | 1:40 | 230 ft/s | 157mph |
| 36,000' | Max safe altitude with Rk 20 Aerial Affinity | 2:40 | 300 ft/s | 205mph |
If the faller is already at terminal velocity, then they will be moving around 1,000 feet every 5 seconds.
- Distance vs. Time at Terminal
| Height | Reason | Time to Ground |
|---|---|---|
| 500' | Time for one action | 0:02.5 |
| 1,000' | Time for trigger or quickened cast | 0:05 |
| 2,000' | Time for cast. Minimum safe flying height | 0:10 |
| 12,000' | Time for minute cast. | 1:00 |
Falling vs. Flying
Falling is simply the fastest means of vertical movement. While Rank 20 windwalk can be slightly faster than falling (below 15,000'), its duration occurs in units of 30 seconds (actual time to ground is given in brackets); even the 5 seconds it takes to counterspell a windwalk uses up more time than can be gained. Falling also costs no fatigue, and requires no skill. Unfortunately, its primary downside (being limited to vertical rather than horizontal movement) prohibits it being taken up as a standard long-distance travel method. However, as a way of descending rapidly or of out-manoeuvring an opponent in a flying battle, it is superior to any other method except a teleportation talent. Note that the times for free-fall or stooping assume these are continued until sea-level, which is not advised. Instead, a faller should have a pre-planned way of dealing with the "crash" when they come off the "high" induced by falling. Pulling out of the dive into an alternative form of flight at two or three thousand feet is the usual way of avoiding the otherwise messy consequences; however this does substantially increase travel time, and experienced fallers may choose to wait until 50 or 100 feet above ground before deciding on their exit strategy.
- Travel Time Comparison
| Height | Free-fall | Stooping | Windwalk Rk 20 (vertical) |
Windwalk Rk 10 (vertical) |
Flying Rk 15 (in steep dive) |
Feather fall |
|---|---|---|---|---|---|---|
| 1,000' | 00:09 | 00:09 | 00:30 (00:05) | 00:30 | 00:30 | 0:17:00 |
| 1 mile | 00:30 | 00:24 | 00:30 (00:24) | 01:00 | 02:40 | 1:30:00 |
| 10,000' | 00:55 | 00:38 | 01:00 (00:46) | 01:30 | 05:00 | 2:45:00 |
| 20,000' | 01:40 | 01:05 | 02:00 (01:31) | 02:30 | 10:00 | 5:30:00 |
| 36,000' | 02:40 | 01:40 | 03:00 (2:44) | 04:30 | 18:00 | 10:00:00 |
Gliding and Tracking
It is nearly impossible to judge your landing spot to within five feet from several miles up. However, an experienced faller can control their direction to some extent, and once they reach terminal velocity, they may move nearly as far sideways as they fall. The overly optimistic claim this is Gliding, but it is more truly called Tracking, as a faller is at best crab-crawling sideways as they plummet. Falling is not a recommended method for controlled or rapid horizontal movement. Skilled fallers claim that they can reach horizontal speeds of up to 100mph, and control their direction within ten or twenty degrees; experienced flyers should expect similar or lesser effects, depending on their attire.
Falling for the Fashion-impared
Often falling is spontaneous, and people can find themselves inappropriately attired. The looks to avoid wherever there is the likelihood of falling include full-length gowns or robes, long flowing lines, ruffles, hoops, and bustles. As always, the little black dress is excellent, as long as you don't let it ride up too high. Jewellery and accessories should be kept to the bare necessities; it is always better to under- than over-dress when travelling. Parasols and fans are a strict no-no even in summer, as are sun bonnets or anything that could be described as a concoction. Hairstyles are a perennial problem when falling - a simple hat or scarf will assist somewhat, but fierce tangles and terminal fluffiness are inevitable unless you apply magical assistance.
At terminal speeds and beyond, the dress code is post-apocalyptic minimal, and this is ruthlessly enforced by the environment. All jewellery and large accessories, including dress weapons, will be stripped from their owners and distributed randomly over the surrounding countryside. It is advised that you keep your hands empty and your arms by your sides at all times. Form-fitting leather and a half-inch crew cut are in vogue for the serious faller, as even Binder Adhesion will not present some wear and tear on your coiffure.
Other Notes and Advice
- Teleporting next to a faller
If a faller is travelling downwards at a near-terminal velocity of 180ft/s (120mph), you teleport next to them, and you start falling immediately on arrival, they will be 500 feet below you in 3 seconds, and 1,000 feet below you within 10 seconds, by which time you should be able to roughly pace their travel. The recommended approach to hitch a ride is to teleport 1,000 feet below a fellow traveller, and rendezvous with them 10 seconds later. Teleporting in and grabbing hold immediately will tend to wrench your arms from their sockets, limiting your ability to make a smooth and controlled landing.
- Learning to Fall
Despite jokes about it being as easy as falling off a log, long-distance falling is a difficult skill to master, and in acquiring it you will inevitably end up with bumps and bruises. There is reputed to be an adventuring skill used by those who regularly plummet from great heights and land without using any means of flying - pulling out into level flight before hitting the ground is merely a use of the flying skill. Falls of under 200 feet can be made safely without resort to such advanced techniques, but any fall over 200 feet is not recommended for amateurs, even if made over water or snow.
