All of this is from Basic RolePlaying, 2008 revision. See Kevin's Rules Changes page for campaign-specific stuff.

Statement of Intent: low DEX to high DEX

Actions:  high DEX first.

Movement:  up to 5 yards = no penalty

                  6 to 15 yards = act at half DEX rank

                  16 to 29 yards = act at quarter DEX rank

                  30 yards = only dodges or parries allowed

Multiple Actions:  at -5 DEX intervals, after the Movement modifiers. If movement and actions brings your DEX rank to 0, you can't make that action.

Multiple Parries in a round are conducted at -30%, cumulative, after the first.

Multiple Dodges in a round are conducted at -30%, cumulative, after the first.

You may not normally Parry and Dodge in the same round.

If a character chooses to "Fight Defensively" (aka "Full Defense") they may Dodge and Parry in the same round. If so, multiple Dodges or Parries in the round are conducted at -30%, cumulative, after the first.

If total wounds reach half or more of your normal Hit Points, make a POWx4% roll or fall unconscious for a while.

If remaining Hit Points are 2 or 1 points, fall unconscious for a while.

If your Hit Points are reduced to 0 or less, you have until the end of the subsequent round for your Hit Points to be raised to 1 or more -- otherwise you die.

The chance to hit with firearms is doubled out to your DEX in feet.