FFX Turn Order

 _____________________________________________
/  a) Determining 'Tick Speed' Using Agility  \
===============================================================================

First, you must be introduced to what Tick Speed is:

From Terence's mechanics data:

"The CTB system works on a system of clock ticks, very similar to FFT. There
are, of course, differences....
Each monster and party member have a counter. Every tick, this counter reduces
by 1. At that point, anyone whose counter has dropped to 0 may take their next
turn. It is not currently known exactly how the game resolves multiple
characters reaching 0 at the same time.
In addition to the counter, every battle object has a tick speed. This is an
integer worked out from the character's Agility. Any action you take will be a
multiple of this tick speed.
When a turn is taken, it sets the counter to a value related to your tick speed
and the ability used. Each ability has a Rank that designates exactly how fast
the ability is. Lower ranked abilities take less time than higher ranked
abilities, and the progression is linear: a Rank 8 ability will take eight
times as long to recover from as opposed to a Rank 1 ability.
The CTB window shows the next 16 turns that will be taken, in whatever order.
It assumes that each character, when their next turn comes up, will select a
Rank 3 move. Rank 3 is the default speed for any ability. Furthermore, the bar
next to each character's 'turn' represents how many ticks away it is. With no
bar showing, the turn is to be taken during the current tick. A full bright
pink bar represents a turn 20 ticks away, and for each further color that is
filled, another 20 ticks is added on. A full bar of the darkest color
represents a turn that is 60 or more ticks away.
Because of all this, there are very few formulas required to explain all this.
We'll cover the most important one now: what the counter is set to when you
take a turn.
The exact value is:
Counter = [Tick Speed*Rank*Haste Status]
...where Rank refers to the Rank of the ability used, and Haste Status is
either 1/2 for Haste, 1 for Normal and 2 for Slow. Keep in mind that when under
Haste status, your Counter will be rounded up if a fraction remains. This often
results in abilities with odd-numbered Ranks used by characters with
odd-numbered tick speeds being recovered from slightly faster than usual.
Casting Haste and Slow also changes the current Counter. A successful casting
of Haste on a character will halve their current Counter while rounding down,
regardless of whether they were Slowed or not beforehand. The opposite happens
with Slow; their Counter will be doubled regardless of whether they were in
Haste or not. Also note that Dispelling either Haste or Slow will *NOT* change
their Counter. Their Counter will continue to descend at the same high or low
value until their next turn."

Now, here's a chart relating Agility to Tick Speed:
------------------------+-------------------------+--------------------------
Agi        = Tick Speed | Agi        = Tick Speed | Agi        = Tick Speed
------------------------+-------------------------+--------------------------
170 -  255   = 3        | 19  -  22    = 10       | 4            = 20
------------------------+-------------------------+--------------------------
98  -  169   = 4        | 17  -  18    = 11       | 3            = 22
------------------------+-------------------------+--------------------------
62  -  97    = 5        | 15  -  16    = 12       | 2            = 24
------------------------+-------------------------+--------------------------
44  -  61    = 6        | 12  -  14    = 13       | 1            = 26
------------------------+-------------------------+--------------------------
35  -  43    = 7        | 10  -  11    = 14       | 0            = 28
------------------------+-------------------------+--------------------------
29  -  34    = 8        | 7   -  9     = 15       | *************************
------------------------+-------------------------+--------------------------
23  -  28    = 9        | 5   -  6     = 16       | *************************
------------------------+-------------------------+--------------------------

 ____________________________
/  b) Initial Counter Value  \
===============================================================================
(Thanks to jobber2022497 for posting this info and allowing me to use it)

The first has to do with the Counter value assigned to each participant at the
start of battle. We'll call this number "Inital Counter Value", or ICV for
short. You may have noticed that the ICV for a given character (without
Haste) is approximately [Tick Speed * 3]. For quick reference, here's the
list of Tick Speed values for each range of Agility:

Agi --------------------------------------------------> TS

0 ----------------------------------------------------> 28
1 ----------------------------------------------------> 26
2 ----------------------------------------------------> 24
3 ----------------------------------------------------> 22
4 ----------------------------------------------------> 20
5~6 --------------------------------------------------> 16
7~9 --------------------------------------------------> 15
10~11 ------------------------------------------------> 14
12~14 ------------------------------------------------> 13
15~16 ------------------------------------------------> 12
17~18 ------------------------------------------------> 11
19~22 ------------------------------------------------> 10
23~28 ------------------------------------------------> 9
29~34 ------------------------------------------------> 8
35~43 ------------------------------------------------> 7
44~61 ------------------------------------------------> 6
62~97 ------------------------------------------------> 5
98~169 -----------------------------------------------> 4
170~255 ----------------------------------------------> 3

In Pre-emptive Strikes and Ambushes, the ICVs of the disadvantaged side
are indeed set to [TickSpeed * 3].

However, in a normal start, [TickSpeed * 3] is only the maximum ICV possible
for characters and the minimum ICV possible for monsters.

For characters, the range of possible ICVs varies greatly within each Tick
Speed. In contrast, monsters have only one ICV range per Tick Speed.

Here is the list of relevant Agility groupings (left column), their
corresponding characater ICV ranges (right column), and monster ICV ranges
("M" entries) in a normal start:

Agi------------------------------------ICV

1---------------------------------------83~84
M: 84~93
2---------------------------------------77~78
M: 78~86
3---------------------------------------71~72
M: 72~80
4---------------------------------------59~60
M: 60~66
5---------------------------------------47~48
6---------------------------------------46~48
M: 48~53
7---------------------------------------44~45
8---------------------------------------43~45
9---------------------------------------42~45
M: 45~50
10---------------------------------41~42
11---------------------------------40~42
M: 42~46
12---------------------------------38~39
13---------------------------------37~39
14---------------------------------36~39
M: 39~43
15---------------------------------35~36
16---------------------------------34~36
M: 36~40
17---------------------------------32~33
18---------------------------------31~33
M: 33~36
19---------------------------------29~30
20---------------------------------28~30
21---------------------------------27~30
22---------------------------------26~30
M: 30~33
23---------------------------------26~27
24---------------------------------25~27
25---------------------------------24~27
26---------------------------------23~27
27---------------------------------22~27
28---------------------------------21~27
M: 27~30
29---------------------------------23~24
30---------------------------------22~24
31---------------------------------21~24
32---------------------------------20~24
33---------------------------------19~24
34---------------------------------18~24
M: 24~26
35---------------------------------20~21
36---------------------------------19~21
37---------------------------------18~21
38---------------------------------17~21
39---------------------------------16~21
40---------------------------------15~21
41---------------------------------14~21
42---------------------------------13~21
43---------------------------------12~21
M: 21~23
44~45------------------17~18
46~47------------------16~18
48~49------------------15~18
50~51------------------14~18
52~53------------------13~18
54~55------------------12~18
56~57------------------11~18
58~59------------------10~18
60~61------------------9~18
M: 18~20
62~65------------------14~15
66~69------------------13~15
70~73------------------12~15
74~77------------------11~15
78~81------------------10~15
82~85------------------9~15
86~89------------------8~15
90~93------------------7~15
94~97------------------6~15
M: 15~16
98~105----------------11~12
106~113---------------10~12
114~121---------------9~12
122~129---------------8~12
130~137---------------7~12
138~145---------------6~12
146~153---------------5~12
154~161---------------4~12
162~169---------------3~12
M: 12~13
170~185---------------------8~9
186~201---------------------7~9
202~217---------------------6~9
218~233---------------------5~9
234~249---------------------4~9
250~255---------------------3~9
M: 9~10

Each single-spaced block of entries represents a distinctive Tick Speed. To
get a monster's ICV range, find its Agility stat and look for the "M" entry
directly below it. For example, Vorban (33 Agility) has an ICV range of 24~26.

Of course, character ICV is halved with [Auto-Haste]. Note that 0 Agility is
not covered by Ultimania; the only known 0 Agility unit in the game is Magic
Urn, and it never gets a proper turn.

So that's it for the first issue of this topic. Scroll down for the next
part. (I promise that it will be shorter!)

As you might already know, a few of the game's monsters will do something
immediately after they appear, regardless of "Pre-emptive Strike"/normal
start/"Ambush" or Agility. For lack of anything better to call them, I've
named such occurences "immediate actions", and they are the second subject
of this topic. Examples of them include Yunalesca[3]'s Mega Death and
Varuna's Haste (when Varuna is encountered outside the Arena).

Immediate actions that are done at the start of battle occur one tick before
Pre-Emptive Strike/[First Strike]/Ambush turns are resolved. Character counters
are not reduced during this tick, but the immediately-acting monster's Counter
is reduced.

In other words, when Kottos (Tick Speed 7) starts the battle by preparing its
counterattack, its Counter is reset to 21, but the Counter goes down to 20
before the characters can take [First Strike]/Pre-emptive Strike turns (it will
be 16 by the time that a 170 Agility + [Auto-Haste] character gets his/her first
turn).

I have not done any thorough testing with it yet, but it seems that immediate
actions cancel out the "Monster Counter -> 0" property of Ambush (at least
with Kottos).

Ultimania Omega has a table that looks like a list of battle-opening
immediate actions, but I do not know enough Japanese to read it all (yet).

* - I've only tested this in battles with a single enemy, so I cannot say if
this holds true for multiple enemies in a battle in which only one enemy has
an immediate action.

Monster ICV's appear to range from, yes, 3x Tick Value to [10*TV÷9] inclusive,
in all cases.

Party ICV's... they appear to depend on how much Agi you have over the base
value. For TVs 7+, it's a simple 1-to-1 basis (if MinAgi is the minimum Agi
required to get a particular TV, then your ICV = (3*TV - 1 - (Agi-MinAgi)) to
(3*TV)).

Below that, though, the range uses a power of 2, transforming the formula to:
ICV = (3*TV - 1 - [(Agi-MinAgi)÷(2^(7-TV))]) to (3*TV)

Slow merely doubles the Tick Counter; it doesn't change Tick Speeds.

And I note I listed [10*TV÷9] for monsters end value, which is clearly
incorrect: I meant [30*TV÷9] or [10*(3*TV)÷9].