First, and this part is ironclad: initiative determines which player/side goes first, while speed determines which action happens first. In other words, initiative is a meta-game concept, not an in-game concept, although I think I'll make the initiative roll double as the surprise roll, which is an in-game concept.
Second, I'm assuming the following:
- I'm only using d20 (for attack rolls and important saves) and d6 (for effects, speed, and non-critical saves;)
- The six primary abilities are in the 3-18 range, with Attribute/3 (round down) recorded after each score in parentheses;.
The die result, including the 1-point "unprepared" penalty, is also used as an initial "surprise save". Each character uses their best score out of Wisdom and Dexterity; or, more specifically, the Attribute/3 rating from 1 to 6. If the initiative result is higher than their Attribute/3, the character is surprised. (There are other possible modifiers, but I'll expand surprise in another post.)
That group initiative result is also the default speed rating. On each succeeding round of combat, the action with the lowest speed goes first. On the second round, players have the option of re-rolling their individual speed, or continue using the group's speed. If they re-roll, they can't go back to the group's speed, but they can roll again on the next round.
The minimum speed of spells is equal to the spell's level. Weapons adjust speed this way:
- weapons that are so heavy that they add +1 to attack rolls also add +1 to speed;
- two-handed weapons add +1 to speed;
- weapons longer than the character is high add an additional +1 to speed;
- small weapons like daggers subtract 1 from speed.
Other things like labels and abilities can adjust an individual's speed as well.