[C3] Action Types

Reading this section in conjunction with [C4] Combat Sequence might be helpful.
Rule [T2.3] gives a brief introduction to action types in the Collective.
P (Physical), M (Mental), V (Movement), Z (Zero/Minor), and S (Standard) actions are the most basic types of actions in the Collective. The other action types are more rare.
The vast majority of characters have either 1P+1M+1V or 1S+1V actions per round.
Normally, each creature/PC can use up to 1P+1M+1V+1Z actions per segment, unless an effect violates this (these are rare effects). In some campaigns, each creature/PC can use up to 1S+1Z actions per segment, where 1S can be 1M or 1P (this is similar to 3rd edition).
Once a creature/PC has used his actions for the round, he does not act again that round. Thus, a creature with 2P+1M+2V (per round) could use 1P+1M+1V on segment 1, then 1P+1V on segment 2, then he is done acting for the round (except for Z actions).
There are 10 segments per round. Most fights will have everyone finished (out of actions) by segments 2 or 3. If everyone in a fight is out of actions for a round, the DM will frequently skip the remainder of the round and move on to a new round.
Action types are given alphabetically, but (again) the most common types used are P, M, V, Z, and S.
There are some very exotic action types that are not listed here (e.g. the Bug class in [PC7], also the Cthulhoid Horror class in [PC8] has several).
A actions:
This is a custom action type. It is loosely based on the "Speed" rating from Angband.
You may spend 1A to get 1V, 2A to get 1P, 3A to get 1M, or 4A to get 1F.
B actions:
This is an improved A action.
You may spend 1B to get 1V, 2B to get 1P, 3B to get 1M, 4B to get 1F or 1QV, 5B to get 1QP, 6B to get 1QM, or 7B to get 1QF.
b (Borrowed) actions:
Not to be confused with B actions above. The prefix "b" is always in front of another action type (e.g. a "bP" action). This is an action that is "borrowed" from your remaining actions for the round. Currently in the Collective, very few effects allow you to use borrowed actions; examples being various counterspells and Psi1 Energy Control. Unless you have an ability that specifically allows you to use borrowed actions, you cannot use borrowed actions for anything.
Borrowed actions are "Opposing" in the sense that they can be used during the opponent's half of the segment.
C actions:
This is an improved B action.
You may spend 1C to get 1V, 2C to get 1P, 3C to get 1M, 4C to get 1F or 1QV or 1QZ, 5C to get 1QP, 6C to get 1QM, 7C to get 1QF or 1QQV or 1 OppV, 8C to get 1QQP or 1OppV, 9C to get 1QQM or 1OppM, or 10C to get 1QQF or 1OppF.
D (Death) actions: (Optional Rule)
Previous versions of the Collective included D actions, I include them here for completeness. Death actions have been shown to greatly disrupt/unbalance game play (even with lots of limits put on them), so be warned as a DM if you allow them.
You get one D action per reset, and can use only one per fight if an effect somehow gives you more.
A D action can be used by a PC (or x2 monster) immediately after being dropped to -11 hp or below. If you dropped yourself or if a friend drops you, you cannot use a D action (unless the act was a true act of betrayal). A D action is an S action, i.e. it can be used as 1P, 1M, or 1V. It could be used as 1Z instead. D actions are both "Opposing" and "Quick".
You may do a hostile action with a D action. You may heal yourself with a D action, putting yourself back to positive hp.
E (Equipment) actions:
These are the actions used by intelligent items and artifacts. It is very rare for a PC to have E actions (unless they have Psi16).
If a PC has an E action, it may be converted to an M action.
An item may use 1E action per segment.
F (Full) actions:
These can be used for any one (single) action that can be done.
You can use 1F+3Z actions instead of the normal 1P+1M+1V+3Z actions per segment.
You can convert 1P+1M+1V to 1F, or all the the actions you can do in 1 round to 1F.
G (Godly) actions:
Immortal (x3 and higher multiplier) powers require G actions to use. See section [X] on how to generate G actions, most x0 to x2 beings can't do it.
G actions can be converted to X actions.
h (Held) actions:
The prefix "h" is always in front of another action type (e.g. a "hM" action). This is an action that is "held"; i.e. you didn't use a particular action in a segment, so you "hold" it to be used during the opponent's half of the segment. Currently in the Collective, very few effects allow you to use held actions. In general, you cannot hold an action and use it on your opponent's segment just because you want to. An ability must be available to use the held action.
Held actions are "Opposing" in the sense that they can be used during the opponent's half of the segment.
Of course, on a given segment, anyone can choose to simply not act, leaving his actions available for later in the round. This is not a held action; this is just actions that were saved for later use in the round.
I (Instantaneous) actions:
These are actions that cannot be responded to. Normally, an action can be responded to using an Opposing action or Zero action. In this case, a "stack" (similar to the Magic the Gathering stack) is created, with the most recent effects added resolving first.
I actions are similar to the "Split Second" (or "Interrupt") ability of Magic the Gathering.
If multiple people wish to use I actions at the same time, the current player (which "half" the segment is on) gets to go first. If both are on the same side (or if neither person is acting during their half of the segment), both people record their intended actions separately, and then both actions resolve simulataneously.
I actions, if there no letter after the "I", are IS (Instantanteous Standard) actions. Otherwise, the letter "I" is given in front of another action type (e.g. an IP is an Instantaneous Physical action).
M (Mental) actions:
These typically are used for spells, psionics, or innate abilities. You get M actions through [P2], based on Int+Wis+Chr.
Spells normally require 1M+1P, if you are of high enough level a spell might require only 1M (see [P4.2] "All Wizards" for info).
N (Null) actions:
This is something that doesn't require an action at all. It is easier to write "1N: blah" than write "Absolutely no action: blah" or "No action at all: blah".
You can use N actions at any time, unless an I action is on the stack. You can use any number of N actions, but the DM may rule that an effect may take time to resolve, so you can't go "infinite" in a single segment.
N actions cannot be generated, gained, lost, lent to others, or locked down. It's not really an action type, it's an abbreviation.
Note that talking and dropping effects use Z actions, not N actions (see Z actions below). Very few things actually use N actions.
Opp (Opposing) actions:
Opposing actions are used during the opponent's half of the segment (see [C4] step 3B). The generic Opp action is a F action.
Opp actions, if there no letter after the "Opp", are OppF (Opposing Full) actions. Otherwise, the prefix "Opp" is given in front of another action type (e.g. an OppP is an Opposing Physical action).
You do not normally generate Opp actions, they are usually granted from a spell, psionic ability, or magic item.
You can use only 1 Opp action each segment, unless they are of different types amongst P/M/V. Adding Quick (Q) to an Opposing action type frequently does not work correctly; e.g. using 9 QC actions to make a QOppM will not work properly. There are some effects that allow Quick Opposing actions, these are rare and are generally in the [PC7] Concordant and [Q7] Godly Psionics sections.
P (Physical) actions:
These typically are used for physical attacks. You get P actions through [P2], based on Dex.
1 P action can be converted to 1 V (Movement) action. This is called "running".
Each body part (except legs) has a set of P actions, so you can use your "Mouth's P action" to use a breath weapon or bite.
Q (Quick) actions:
The prefix "Q" is always in front of another action type (e.g. a "QV" action). Quick actions can be used in addition to the 1P+1M+1V+3Z limit per segment.
Thus, you could use an M and a QM in the same segment.
You can't use more than one Quick action of the same type in a single segment, unless it is "Quick Quick" (such as a QQP). You could use 1P, 1QP, and 1QQP all in the same segment (and 1QQQP if you have one).
A Q action is "infinitely quick"; any number of these can be used per segment. Thus, if you have 8 QP actions, you can use them all in the same segment. These action types are very rare (the Warlord class in [PC7] is one source of this).
S (Standard / Swing) actions:
These are the Standard actions from 3rd edition. M and P actions are in a sense limited S actions that can be used only for Mental (M) or Physical (P) things.
1S can be converted to 1P, 1M, or 1V. You do not generate S actions, they are granted from a spell, psionic ability, or item.
V (Movement) actions:
These typically are used to move, for kicking, or material componenting of spells (see [S1]). You get V actions through [P2].
Moving is rated in inches ("), each inch is 10 feet in the dungeon (10 yards in the wildnerness).
Standing up is a V action, it uses 1" of movement per 1' of your height (a 6' human with 12" move could stand then move 6").
You can pick something up with a V action. Note you *cannot* move and pick something up the same segment, unless it's a very minor movement (see Z actions). You can drink a potion with a V action (also uses your mouth's P for the segment).
X (Spirit / Concordant) actions:
These are actions used by Concordant classes [PC7] (x2 multiplier beings). You may use an X action in addition to the other types of actions you are allowed to use per segment (either 1M+1P+1V+1X per segment or 1S+1V+1X per segment, depending on the campaign).
X actions can be converted to F actions.
Z or 0 (Minor or Zero) actions:
The following things can be done with a Z action:
1. Very minor (less than 3') movement, turning around, or dropping to the ground.
2. Dropping, putting away, and/or drawing weapons or equipment.
3. Dropping a spell or psionic effect.
4. Talking, as long as no verbal component spells are cast in the same segment.
5. Using a psionic defense.
Z actions are free, you may use them at up to 3 per segment.
Z actions may be used during the opponent's part of the segment, but you are still limited to 3 per full segment.
Z actions are frequently denoted as a 0, such as "0, 1/r: Cure 1 hp". The "0" there means a Z action. If there is not a 0 there (such as "1/r: Cure 1 hp"), it requires no action at all to use, unless it is obviously an innate ability which requires 1M.
Optional Rule #1: Increase the 3Z/segment limit to something higher, such as 5Z, or even unlimited (which is the original rule).
Optional Rule #2: Make Z actions unlimited, but the PCs can use only their level in Z actions per round. (Or perhaps 2*level)