The Speed System

Speed is one of the most important character (and monster) attributes 
in the game; but it works in complicated and at times unintuitive ways. 
Player and monster speeds can be displayed in either of two formats: as 
raw speeds like -10, +0 or +10, where +0 is normal speed; or as energy 
multipliers (effective speeds) such as 0.5x, 1.0x and 2.0x, where 1.0x 
is normal speed. The effective_speed display option (see [a]) toggles 
between these display methods; effective speeds are the default in 
Beginner Mode (they help explain to new players the practical meaning 
of an otherwise obscure number), while raw speeds are the overall 
default and what most experienced players are accustomed to.

For new players it should be enough to read the quick overview below; 
the subsequent sections are highly technical, and explain the inner 
workings of the speed system.

Quick Overview for Newbies

Speed is hugely important, especially in the early game. More speed 
means you get more turns compared to everybody else, whatever it is you 
are doing - walking, fighting, zapping devices, or just standing there 
taking way more punishment than you'd like. Often, replacing a damage 
item with a speed item not only improves your speed, it effectively 
also improves your damage output - yes, you might do less damage per 
turn, but you also get more turns to deal damage in!

Potions of Speed, which provide a temporary +10 speed bonus, are your 
first and most important source of extra speed when you are getting 
started. Going from +0 speed to +10 speed doubles your effective speed, 
which needless to say makes an enormous difference! Potions of Speed 
are not particularly rare, so use them freely, but not too freely - 
unless you have a very large pile of them, it is best to save them for 
situations where you really want to take on a particularly dangerous 
monster (quests and dungeon boss fights come to mind!), and for sudden 
emergencies like confusion lock ([b]).

Up to a raw speed of +26, the effects of extra speed are linear - +0 is 
1.0x, +1 is 1.1x, +2 is 1.2x, +5 is 1.5x, +10 is 2.0x and so on. This 
already means the returns for having more speed are diminishing: the 
move from +0 to +10 (1.0x to 2.0x) doubles your speed, but +10 to +20 
(2.0x to 3.0x) is only a 50% increase. After +26/3.6x, though, the 
returns become even more diminishing - in fact, +27 is still 3.6x, the 
extra +1 speed does nothing! +28 does give you 3.7x speed, and piling 
on enough additional bonuses can eventually take you as high as 
+70/4.9x, the highest effective speed possible.

If a monster is faster than you, it will occasionally get two moves in 
a row against you; this is commonly known as a double-move, and is 
often very dangerous. An extremely fast monster might even triple-move 
or quadruple-move you! Of course, if you are faster than a monster, you 
can turn the tables...

The practical effects of speed are somewhat random, so you might 
occasionally be double-moved by a monster who is technically slower 
than you, or in turn double-move a monster faster than you are.

Despite the high importance of speed, it is not the be all and end all; 
you may want to compromise your speed to keep key resistances covered, 
to get your stats up, or to equip a weapon with extremely high damage; 
and Potions of Speed and other sources of temporary speed provide a lot 
of help when it matters the most.

Technical Explanation

    This and the following sections cover the energy 
    system, a very advanced topic, and largely consist of 
    detailed, highly technical explanations of why all the 
    easily understandable explanations given elsewhere are 
    oversimplified. Full understanding of the energy system 
    is in no way required to play and enjoy the game.

Almost every action you take in the game - walking, casting a spell, 
hitting a monster, drinking a potion, refueling a lamp - consumes a 
certain amount of energy. Most actions eat up exactly 100 energy, and 
so actions that cost 100 energy are frequently glossed as costing "1 
turn" while 200 energy is "2 turns" (and 50 energy is "half a turn"); 
this is technically inaccurate in more than one way, but still explains 
the practical difference nicely.

Actions themselves are instantaneous - it is recovering the lost energy 
that takes time. This is where speed comes in. A speed of +0 (1.0x) 
means you recover 10 * 1.0 = 10 energy per game turn; a speed of 
+20/3.0x means you recover 10 * 3.0 = 30 energy per game turn. The 
usual action cost being 100 energy, it will take many game turns of 
silent energy recovery until you get another player turn - but monsters 
might spend those game turns doing something else besides...

The table below shows every possible speed from -50 to +99, and the 
energy recovery per game turn for each, indicated in blue. (There is no 
underlying formula - the game is looking at the same table you are.) 
Note the linearity of the table between -3/0.7x and +26/3.6x; most of 
the game will be spent within this linear range.

Speed/Energy Conversion Table

    -50    1,  1,  1,  1,  1,  1,  1,  1,  1,  1   -41
    -40    2,  2,  2,  2,  2,  2,  2,  2,  2,  2   -31
    -30    2,  2,  2,  2,  2,  2,  2,  3,  3,  3   -21
    -20    3,  3,  3,  3,  3,  4,  4,  4,  4,  4   -11
    -10    5,  5,  5,  5,  6,  6,  7,  7,  8,  9   -1
     +0   10, 11, 12, 13, 14, 15, 16, 17, 18, 19   +9
    +10   20, 21, 22, 23, 24, 25, 26, 27, 28, 29   +19
    +20   30, 31, 32, 33, 34, 35, 36, 36, 37, 37   +29
    +30   38, 38, 39, 39, 40, 40, 40, 41, 41, 41   +39
    +40   42, 42, 42, 43, 43, 43, 44, 44, 44, 44   +49
    +50   45, 45, 45, 45, 45, 46, 46, 46, 46, 46   +59
    +60   47, 47, 47, 47, 47, 48, 48, 48, 48, 48   +69
    +70   49, 49, 49, 49, 49, 49, 49, 49, 49, 49   +79
    +80   49, 49, 49, 49, 49, 49, 49, 49, 49, 49   +89
    +90   49, 49, 49, 49, 49, 49, 49, 49, 49, 49   +99
           0   1   2   3   4   5   6   7   8   9
    
Energy Randomness

The energy costs of all actions are somewhat random. Walking 1 square, 
for example, nominally costs 100 energy; but on any one occasion, the 
cost might be as low as 67 energy if you are really lucky, or as high 
as 133 if you are unlucky. This sounds like a very large range, but it 
generally feels much narrower in play; the cost will usually stick 
fairly close to the nominal value, and even when it wanders off to the 
upper or lower limits, the practical effect is usually small enough to 
not be noticed by the player. The randomness is also more limited at 
higher speeds. Nevertheless, every once in a while it does make itself 
very noticeable in an extremely painful way...

Energy randomness has two important effects on the game. It greatly 
reduces the effectiveness of pillardancing, monster kiting and other 
old Angband strategies that rely on an enemy doing what you expect when 
you expect it. It also increases the frequency and unpredictability of 
double-moves, and means you can be double-moved by a monster nominally 
slower than you. For such a double-move to not just occur but occur in 
a way that really hurts you, you will have to be very, very unlucky - 
but it's a long game with many opportunities for bad luck to hit you...

The double-move threat can be handled in any (or all) of several ways: 
you can pile on more and more speed to reduce the frequency of monster 
double-moves; you can invest in hit points and resistances (and heal 
yourself as early as reasonable) to make the double-moves that happen 
more survivable; you can try to keep fights against potentially deadly 
double-movers to the absolute minimum; or you can simply accept the 
non-zero but low risk of death, and count on it not happening; such 
brave play can even help indirectly by allowing faster progress.

Energy Cost of Actions

While most player (and monster) actions consume 100 energy before 
randomness is accounted for, this rule is by no means universal. 
Walking into a normal square might only cost 100 energy; but walking 
into a tree square consumes 200 energy because you have to find your 
path and dodge all those low-hanging branches. (Levitating players, and 
a few races like Ents and Centaurs who feel particularly at home in 
forests, can move in wooded areas at normal speed.) Likewise, for most 
races walking in snowy areas without Levitation consumes 133 energy at 
a minimum - more if you are badly overburdened and get bogged down in 
the snow. The good news is that monsters receive similar penalties!

The action cost of archery depends on how many shots you get per round; 
if you have 1.6 shots per round, that simply means each individual shot 
only consumes 100 / 1.6 = 62 energy (and so you would be at less risk 
of a nasty double-move while shooting!). Note that melee blows do not 
work in the analogous way; a turn of melee always consumes a nominal 
100 energy, except in the special situation where a Beorning in bear 
form, a Berserker or a character with the Fantastic Frenzy demigod 
talent kills a monster in the middle of the round.

Some spells and class powers have special action costs, costing less 
(or more commonly more!) than the standard 100 energy. Changing shape 
as a Beorning, for example, costs 200 energy; and Hounds can activate 
the Stalk toggle without any energy cost at all.

Even the cost of common actions like walking and book spellcasting is 
not completely fixed. The Fleet of Foot demigod talent ([c]) reduces 
the energy cost of walking by 40% (from 100 to 60); Quick Walk on 
Ninjas (and Ninja-Lawyers) is even more effective. Yellow-Mages can 
cast spells extremely rapidly, consuming far less than 100 energy per 
spell; Yeqrezh Disciples with the Quick Spelling gift can also cast 
spells rapidly, though not as fast as Yellow-Mages. Devicemasters can 
use their speciality devices in less than a full turn.

Temporary Haste and Slowness

Temporary effects can make you significantly faster or slower. 
Temporary speed or haste usually refers to a speed bonus of +10; this 
is what Potions of Speed and spells like Haste Self provide. As noted 
above, this can double (or potentially more than double) your speed in 
the early game! In the late game, when your unhasted base speed is 
higher, the effects of temporary speed will be less dramatic; yet it 
remains strong enough to be a key part of your toolkit into the latest 
parts of the game. Staves of Speed and Rods of Heroic Speed may even 
allow you to spend almost the entire endgame hasted.

Temporary slowness is usually caused by monster spells or attacks, 
although it can also be induced by other sources like traps, potions 
and mutations. It comes in two different forms: a lump penalty of -10 
to speed (the opposite of haste), and incremental mini-slowness that 
can range from -1 to -10. These two types of slowness partially 
combine, for an overall penalty of up to -12 if you are afflicted with 
both; see [d] for more detail.

Monster Speed

Monsters use the same speed system players do; they use the same energy 
table, they usually consume 100 energy per action (and apply the same 
energy randomness formula), they recover energy the same way players 
do, they can be temporarily hasted or slowed in the same ways; they 
receive similar (though not always identical) energy cost penalties for 
certain moves, like entering a tree square without the ability to fly 
or pass through obstacles.

One important note, though, is that individual non-unique monsters can 
be somewhat faster or slower than the average for their race. If you 
are at +2 speed and still getting double-moved by a "+0 speed" hill 
orc, you might just be unlucky with the energy randomness... but you 
might also be dealing with an unusually fast orc. Probing such a 
monster will reveal its individual speed.

Where Do I Get More Speed?

Even with a Rod of Heroic Speed, temporary speed can only take you so 
far; sooner or later, you need to get your unhasted base speed up as 
well. You might get some speed from your race, class, personality or 
mutations; but the most important source of speed bonuses will always 
be your equipment. Rings of Speed, Boots of Speed, and artifacts and 
ego items with speed bonuses will eventually take you to +16 (meaning 
+26 hasted!) and most likely well beyond.

Speed items, like most items, can drop anywhere; but if you desperately 
need a speed item specifically, there are three good places to look. 
The Cloning Pits quest is fairly dangerous, and its rewards are random 
within limits; but quite often the reward will be a pair of valuable 
artifact boots with a speed bonus on it. The Underground City quest is 
even more dangerous, but a Ring of Speed is guaranteed to appear there, 
and is often stronger than other speed rings at the same depth. 
Finally, there is a jeweller in the town of Zul who sells rings and 
amulets, often including Rings of Speed and sometimes an Amulet of 
Trickery with speed bonuses. He might even bring out new merchandise if 
you pay him enough!

Note that if you ride a pet, your speed (for all purposes!) will depend 
entirely on your Riding skill and the speed of your mount. Speed 
equipment will not help you any, nor will quaffing a Potion of Speed; 
you can, however, temporarily haste the mount. Many mounts are very 
fast, allowing you to reach a high speed without much investment in 
speed equipment - but watch out, that could come back to bite you if 
you get thrown off...

Overburdening

You can only carry so much weight without it slowing you down; and 
overburdening is the bane of speed, especially for early-game 
characters with low Strength.

Your burden limit ranges from 50 pounds at minimum STR to 195 pounds at 
maximum STR; and all carried objects - your inventory items, your 
equipment, the projectiles in your quiver, even the ice bag and 
infusions of an Igor Alchemist - count towards that limit. The i Show 
Inventory command (and the closely related e Show Equipment command) 
include a line showing the total weight of all items presently carried, 
and how it compares (as a percentage) to the maximum capacity. If the 
percentage exceeds 100, you are overburdened.

Mild overburdening does not actually affect your speed at all (although 
it will cause you to drown in deep water if you lack Levitation). The 
first -1 to speed kicks in at 120% of capacity, with another -1 for 
every additional 20 percentage points. This doesn't sound too bad (and 
mostly isn't!), but in the early game it can get very severe. The most 
common cause of truly major overburdening is exceptionally heavy quest 
loot (in which case the quest is hopefully over, and you can soon sell 
the loot or drop it at home); but unexpected severe overburdening can 
also happen if you spend too much time around strength-drainers...

Riding characters have special burden limits, which depend on their 
Riding proficiency and the level of the mount.

Speed Display

Unless your speed is exactly +0, it will be displayed in the main 
screen sidebar, below the hit points, spell points and various 
health/status bars.

The coloring of the sidebar speed display varies depending on your 
status. The examples below show raw speeds, but the same colors are 
used to display effective speed:

   Fast (+43)    Player is temporarily hasted
   Fast (+43)    Player is riding a hasted mount
   Fast (+33)    Player is faster than +0, but not slowed or hasted
   Fast (+33)    Mount is faster than +0, but not slowed or hasted
   Fast (+23)    Player is temporarily slowed or riding a slowed mount
   Fast (+33)    Player is temporarily hasted and slowed in equal amounts
   Fast (+21)    Player is filibustering (Politicians only)
   Slow (-3)     Player is slower than +0, but not slowed or hasted
   Slow (-3)     Mount is slower than +0, but not slowed or hasted
   
As noted at the top of this document, speed displays can show either 
the raw speed or the energy multiplier (effective speed). Both display 
methods have their advantages and disadvantages. Raw speed is affected 
by bonuses and maluses in intuitive ways - if you start with +2 speed 
and add a -10 penalty, you end up with -8 speed. What it doesn't tell 
you, though, is what -8 speed actually means! Effective speed will tell 
you the -10 penalty took you from 1.2x speed to 0.5x speed - your speed 
was cut in less than half! - which is important practical information; 
but it leaves it quite mysterious why a speed of 1.2x plus a -10 
penalty should add up to a speed of 0.5x. While only one display method 
is used at a given time, it helps to understand both, as each is 
explained by the other.

A slightly different speed display appears near the top of your 
Character Sheet; this display uses generally similar coloring, but 
shows the base speed and temporary effects separately. It is also the 
only speed display in the game that always displays the raw speed; if 
you otherwise you effective speeds, it is the other place (besides the 
[e] conversion table above) that will tell you what your raw speed is.

Duration of Timed Effects

There is a fundamental disconnect between game turns and player turns. 
In the early game, with actions costing 100 energy and the player (at 
+0 speed) recovering 10 energy per game turn, there are on average 10 
game turns to each player turn... but that discounts energy randomness, 
and not all actions have the same cost! Walk into a tree and you have 
20 game turns to a player turn; quaff a potion of speed and you have 
only 5 game turns to a player turn; sleep for the night at the inn, and 
40,000 game turns might go by in the blink of an eye.

Game turns are when the game processes the player, the monsters, and 
everything else; but it is also possible to think of a game turn as a 
fixed unit of time. Indeed, game dates and the day-night cycle are 
based entirely on the game turn as the underlying unit, with 100,000 
game turns corresponding to 24 hours.

A player turn, on the other hand, does not represent any fixed amount 
of time; it is simply an opportunity to do things and to consume 
energy, which itself cannot be directly converted to either game turns 
or player turns.

This disconnect is the key to understanding durations and why they 
sometimes work in unintuitive ways. Durations usually correspond to a 
fixed amount of time, and so do not correspond to a fixed amount of 
player turns; a duration of "25 turns" actually means 250 game turns, 
which is 25 "average" player turns at +0 speed, but could easily mean 
100 actual player turns by the endgame.

Some oddball timed effects are decremented on player turns rather than 
on every tenth game turn, and so their durations correspond to player 
turns and not time. Effects of this type include temporary Light Speed 
and the No Spells status. For all other effects you can safely assume 
that any durations displayed use a unit of 10 game turns.

Wounds and the poison counter are processed once per player turn, the 
poison counter being fully independent of time. (Wound damage adjusts 
for time, so the total cut damage suffered is ultimately the same over 
a fixed amount of time rather than a fixed amount of player turns.)



Original   : FrogComposband 7.1.salmiak