From page 171, "Initiative is determined once for the whoe combat and then remains the same every round."

What if a combatant switches weapons?

What if a militant spell-caster enters into combat with a sword and in later wants to cast a spell?

What if someone is Brawling and decides on some given turn to kick (-2 initiative?)

Ill prefece this by saying I am fairly new to ars magica... But i would adjust the current inititive score by the -2 for the kick or whatever the penalty would be for that round and that would readjust the initive order.

I read the rule as saying you roll inititive once and those numbers are your base for the entire combat and if someone changes strategy they those numbers are adjusted by the inititive penelty but not re-rolled. Just my 2 cents

// I read the rule as saying you roll inititive once and those numbers are your base for the entire combat

That's the way I play it, too. So I add my 2 cents and now we have at least 4 cents.