ADVANCER Initiative

AD&D initiative is not well-explained. It tries to add realism by dividing the 1-minute round into 6-second segments. 

One purported intent was to penalize spellcasters, especially priests (clerics and druids) and high-level magicians (mages and illusionist), whose spells take a half-round or more to cast and thus may be interupted even if the spellcaster wins initiative.

Theoretically, it also allows the GM to adjudicate the relative timing of different actions that require time to complete. I say "theoretically" because the rules in AD&D are not clear about how to actually accomplish this. 

The draft ADVANCE rules are set out below. Here is a quick summary:

- High roll wins initiative. 

- "Immediate attacks" of the winning side occur on segment 1.

- The higher initiative die indicates when "immediate attacks" of the losing side occur (following DMG, p. 65).

- The lower initiative die acts as a penalty for certain actions, specifically:

     - for the winning side, it is added to casting time when spellcasting in melee

     - for the losing side, it is added to the time to complete a timed action (eg, casting time) when adjudicating the relative timing of timed actions (eg, spellcasting) on both sides

- The idea to use the lower initiative die as a penalty on spellcasting in melee was inspired by the "Other Weapon Factor Determininants" rule on pp. DMG, 66-67 (even though the ADVANCER Rules don't use weapon speed factor).

- As an aside, I had an epiphany that, instead of taking the difference between the two initiative dice, one could simply use the lower initiative die as the distribution is the same (out of 15 possible losing initative combinations, there are 5 ones, 4 twos, 3 threes, 2 fours, and 1 five).

ADVANCED Initiative Rules:

1. "Immediate attacks" of the winning side go first:

- Missile attacks

- Turn undead

- Breath weapons

- Gaze attacks

- At-will powers (including those of monsters and magical devices)

- Melee attacks (with some exceptions)

2. Timed actions of the winning side also go first if they require only 1 segment to complete, including:

- Spellcasting (excluding spellcasting in melee)

- Magical device attacks

- Charging attacks

3. Timed actions and delayed actions of winning side vs. immediate attacks of losing side:

- Compare the number of segments of the timed or delayed action to the higher initiative roll (2-6):

     - If less, the timed or delayed action occurs first.

     - If equal, the actions occur at the same time.

     - If greater, immediate attacks of the losing side occur first.

4. Special rule for spellcasting in melee:

- Compare the casting time of the spell plus the lower initiative roll (1-5) to the higher initiative roll (2-6)*:

     - If less, the spell is cast first.

     - If equal, the spell is cast at the same time as the immediate attack(s) of the losing side.

     - If greater, the immediate attack(s) of the losing side occur first.

*If the losing side is taking a timed action in melee (such as using a magical device or casting a spell), add the number of segments requried to complete the timed action.

5. Timed or delayed actions of winning side vs. timed or delayed actions of losing side

- Compare the number of segments to complete each action, adding the lower initiative die (1-5) to the number of segments to complete the actions of the losing side:

     - If less, the timed or delayed action of the winnings occurs first.

     - If equal, the actions occur at the same time.

     - If greater, the timed or delayed action of the losing side occurs first.

6. In the case of tied initiative:

- All immediate attacks occur simultaneously on the segment given by the initiative die (1-6).

- Timed actions and delay actions commence at the beginning of the round, so each occurs on the segment given by the number of segments to complete the action.

7. Out-of-initiative actions

- Immediate attacks of hasted/slowed characters (occur at the beginning and end of the round (segment?))

- Melee attacks of fighters with multiple attacks (occur at the beginning and end of the round (segment?))

- Charging attacks (occur on the segment given by the number of segments to complete the charge)