Can a horse really travel over 65 miles per day, according to the rules?

Question

Special Travel Pace (DMG p. 242–243):

• In 1 hour, you can move a number of miles equal to your speed divided by 10.
• [...]
• For a fast pace, increase the rate of travel by one-third.
• For a slow pace, multiply the rate by two-thirds.

The Variant: Encumbrance rule (PHB, p. 176) says that carrying less than 5 times your Strength score doesn't slow your speed. And per the Lifting and Carrying rules:

For each size category above Medium, double the creature's carrying capacity and the amount it can push, drag, or lift. For a Tiny creature, halve these weights.

So a Riding horse has a Strength score of 16, is Large so that's up to 160 pounds (16 × 5 = 80 then 80 × 2 = 160), not slowed. It has a speed of 60 feet (or 6 miles an hour) when traveling at a normal pace. This is increased by one-third when traveling at a fast pace; 6 × 1⅓ = 8.

You can travel 8 hours a day without exhaustion. Plus you can gallop (inside that 8-hour limit) at double the normal pace (6 × 2 = 12) for 1 hour. It makes the most sense to go fast for 7 hours (7 × 8 = 56), then gallop the last hour (1 × 12 = 12), for a total of 56 + 12 = 68 miles a day.

That's 226.66% the distance that an "unslowed" human party could travel on foot at a "fast pace" (30 miles in the same time period). That's equal to a fifth of the width of Florida! To do the math, this horse could cross the whole USA in under 31 days!)

Is this right?

Seems my math is a bit off for rounding (must round down always in 5e), but SevenSidedDie's comment on GcL's answer says:

The rounding rule is just about direction of rounding. Normal math rules are otherwise used—which means, don't round until the whole calculation is finished. (Rounding after each step in multi-step math calculation is verboten by the normal rules of math because it causes errors.) Since the only change to normal math rules 5e makes is which direction to round, normal math rules apply to 5e rules in all other ways.

So at the very least, in 8 hours, 8 x 7 = 56, plus the one-hour gallop for 12 more, total 68? if a horse isn't limited to the same movement as that of humans with a 30-foot speed listed in PHB p. 182, which RAW, other than galloping once per "long" rest (I'm reading between the lines): IT IS.

MAJOR ADDITIONAL INFO

XGtE (Xanathar's Guide to Everything) page 80, cobblers tools note: must have cobblers tools and be proficient with them

Maintain Shoes. As part of a long rest, you can repair your companions shoes. For the next 24 hours, up to six creatures of your choice who wear shoes you worked on can travel up to 10 hours a day without making saving throws to avoid exhaustion.

so 2 extra hours travel or up to 8 EXTRA miles, if you wear PC race footwear, so NOT A HORSE (38 miles total, beating horses RAW of 34 miles)

Answer 1

The calculation is incorrect, but still could be useful.

tl;dr special travel pace doesn't strictly apply as asserted and rounding goes down, but the result could be an upper limit to temper expectations.

1. Special Travel Pace doesn't strictly apply

...When a creature is traveling with a flying speed or with a speed granted by magic, an engine, or a natural force (such as wind or a water current), translate that speed into travel rates using the following rules...

A horse is neither powered by magic, an engine, nor natural force. But let's carry on with the calculation regardless, because it might be a useful upper bound of possibility.

2. Rounding in 5e is round down

Your 7.98 becomes 7.
But 6mph increased by one-third is actually 6 * 4/3 = 8mph.

3. Upper Limit

This changes the calculation to be (7hrs @8mph) + (1hrs @12mph) = 68 miles. That's maximum pace in good weather and on good terrain. Which seems pretty crazy, but let's consider that the absolute upper limit

4. Check against Phantom Steed example

The phantom steed example at the end of the special travel section gives the results for a hour of travel on a magic horse. 8hrs @13mph = 104. So the fastest pace of a mundane horse in optimal conditions while slightly misusing the rules is 60% of a magic horse. The sanity check is that this calculation still does not beat out a magic horse.

DMG p 243

Similarly, a phantom steed spell creates a magical mount with a speed of 100 feet that doesn't tire like a real horse. ... In 1 hour, the character can travel 7, 10, or 13 miles.

5. Sustained fast pace will likely end in injury and disaster

With some assumptions and optimal conditions, the numbers do work out to be very impressive, but few things in an adventure go by the numbers. Traveling at fast pace increases the risk of accident, injury, and disease. Do not expect your stories to involve regularly traveling at maximum hypothetical pace without risk.

6. Useful upper limit

This could be the upper limit of a herculean effort in order to get a message between two points. As a story point, the 65 miles distance could be considered impossible by anyone sane. But maybe... just maybe with some luck, magic, and the best horse ever it just might be doable to save the day.

Answer 2

No, a horse can't travel this quickly

The rules you've found in the DMG under Special Travel Pace aren't for mundane methods of locomotion like riding a horse:

A character bestride a phantom steed, soaring through the air on a carpet of flying, or riding a sailboat or a steam-powered gnomish contraption doesn’t travel at a normal rate, since the magic, engine, or wind doesn’t tire the way a creature does and the air doesn’t contain the types of obstructions found on land. When a creature is traveling with a flying speed or with a speed granted by magic, an engine, or a natural force (such as wind or a water current), translate that speed into travel rates using the following rules: [...] (DMG p.242)

These rules are specifically for special methods of travel above and beyond mundane transportation, justified by the fact that the methods involved are tireless or otherwise very efficient (i.e. a flying creature does not have to worry about terrain). A normal horse is not flying, powered by magic, an engine, or wind or water or other natural force; it's just a creature walking on land, so it moves according to the normal travel rules given in the PHB, which also notes that:

Certain special mounts, such as a pegasus or griffon, or special vehicles, such as a broom of flying, allow you to travel more swiftly. The Dungeon Master’s Guide contains more information on special methods of travel. (PHB p.182)

Which again rules out using the special travel pace rules for a mundane horse.

A horse ridden at a fast pace therefore covers 30 miles per day as described by the PHB. Despite horses having a greater base speed than most characters, the game rules that's only really relevant for combat, and most creatures move at roughly the same rate for overland travel, as the DMG describes:

The rules on travel pace in the Player’s Handbook assume that a group of travelers adopts a pace that, over time, is unaffected by the individual members’ walking speeds. The difference between walking speeds can be significant during combat, but during an overland journey, the difference vanishes as travelers pause to catch their breath, the faster ones wait for the slower ones, and one traveler’s quickness is matched by another traveler’s endurance. (DMG p.242)

You could plausibly run the horse at a "gallop" (or more realistically a trot) for an hour of that travel, which doubles its speed for one hour to a total of about 34 miles in a day. You could travel further by spending more than 8 hours on the go, but you and the horse would probably become quite exhausted by doing so. If the journey is such that you have the opportunity to switch to a fresh mount every hour, you could theoretically cover about 64 miles in eight hours of travel!

However, remember that the travel speeds given assume good conditions - open plains or roads, clear weather, etc. Following roads may require taking more circuitous routes, and travelling off-road means you're likely to spend some of your time traversing difficult terrain, over which areas your speed is cut in half - so in practice, a horse is unlikely to actually be able to make 34 miles in a straight line. I'd personally also rule that particularly severe weather like a strong storm effectively makes difficult terrain for a journey on foot or by mount.

Answer 3

Reality checks don't fit well with D&D, but the end figure of crossing the United States in 31 days isn't far from correct.

This answer gives an elapsed figure around twice that for real world horses -- and that's plenty close for game purposes. There's nothing that says a DM can't adjust these rates. And, of course, if you travel the way folks did when they wanted to cover a lot of ground, you'd take advantage of relay stations, using letters of credit to trade horses. In the extreme case, this could let Pony Express riders travel at a canter or gallop for most of each riding day, and move mail and small packages from St. Louis to San Francisco in just a few days.

Answer 4

No, but...

The rules for movement feature a table and this sentence:

A mounted character can ride at a gallop for about an hour, covering twice the usual distance for a fast pace.

So, without considering any optional special rules, a mount simply allows a character to use her mount's gallop feature to move a little more quickly for an hour. If that hour of galloping isn't used, the character's travel pace is no quicker than the normal movement as listed on the table.

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Ignoring the rules for a second, it's worth pointing out that a rider for the famous Pony Express could average about 75 miles per day and a message could travel from one coast of the United States to the other in about 10 days.

The horses were ridden for about 10 miles before being exchanged but that ten miles was covered at speeds of 15 to 25 miles per hour, WAY faster than the speeds of the table linked above:

During his route of 80 to 100 miles, a Pony Express rider would change horses 8 to 10 times [ie ~10 miles per horse]. The horses were ridden at a fast trot, canter or gallop, around 10 to 15 miles per hour and at times they were driven to full gallop at speeds up to 25 miles per hour.

And that stamina was achieved without any sort of magical aid. So I think that, in this context, reality is actually a bit more incredible than the rules of a game with magic and so a DM can play a little loose with the rules without being in danger of absurd speeds.