In my table, that's how it goes:
The player with the 'action' (on the spot) says what he wants to do. When there is an attack, it's rolled normally. On a 6-, he is attacked, on a 7 to 9, he causes and receives damage, and on a 10+, he just causes damage. The other player may opt to cause damage or do other thing (like running, grabbing, desarming).
When he finishes his action, the attacked one may act. Basically, that's it.