"Taking Initiative"

Here is an initiative system you may enjoy. I'm unsure if this has been done before but I haven't seen anything exactly like it anywhere so I will post it here. This is the system currently in the Fire Tales RPG playtest:

The character or characters that strike first, go first. This is called “Taking Initiative.” To strike first, the player might say something like “I stab the knight with my dagger” or “I’m going to cast a spell targeting the wizard” in the middle of a conversation or while their enemy is monologuing. Then after this action, the order goes based on a static initiative attribute each creature has. In the event of an ambush, the ambushing group each acts in the order of their static initiative and then the ambushed group acts.

The trick is to have static initiative values based on something that is almost always unique. I current have this value set to 2DEX + WIS, with the tiebreaker being who is closer to where the action starts, but I may adjust this initial value to be something where overlap in values happens less often. 

Florence Harrison