I'm starting up a new thread to answer this question to keep it distinct.
To stress a point that needs to be constantly reinforced: this game is in playtest mode, meaning the rules played today are different from the rules played yesterday. We're trying different ideas at different sessions, trading notes, and tweaking constantly. What you're about to read is the result of that tweaking and not yet final...but definitely moving in the right direction.
Regarding the specific question, something DCC RPG tries to achieve is the feel of pre-D&D sword & sorcery. In practical terms, that means not just interesting magic, but also amazing stunts by warriors.
In game terms, D&D has done this for generations and consistently created complex sub-systems as a result. 3E did it with feats, 4E with powers, prior systems with other mechanisms, and they tend to create complexity and limit the warrior far more than what the literature suggests. Conan, Elric, and John Carter didn't specialize in a single weapon style or a special type of fighting to become they heroes they were. They were good at it all.
What I'm playing with right now is base attack bonus. In traditional D&D, fighter types get +1 at level 1, +2 at level 2, +3 at level 3, and so on. In DCC RPG right now, warriors get d3 at level 1, d4 at level 2, d5 at level 3, and so on.
By "d3 at level 1," I mean the warrior rolls a d3 on every attack roll. This attack is d20+d3+Str mod; next attack is d20+d3+Str; etc. It's not a d3 made at the level-up time, but rolled anew every attack.
The sum of these dice forms the attack roll, which is compared to AC as usual.
If the overall attack roll hits, AND that d3 is a 3 or better, the warrior can perform a cool stunt declared at moment of attack. We call this a Mighty Deed of Arms.
Examples of actual Mighty Deeds performed in play:
* When fighting opponents on a staircase, someone used a sword to stab the opponent and then lever them over the edge of the staircase
* In the same battle, someone attacked the foe's legs to knock them off balance and off the staircase
* When fighting a carven image with eyes that shot laser beams, a warrior used a mace to smash out the carved eyes (and thus disarm the laser beams)
* When fighting a basilisk with a hypnotizing gaze, a warrior tried to stab it in the eye to disable its gaze
* When fighting a flying skull that was out of melee reach, a warrior tried to leap off the back of another character into a flying lunge that connected with the skull in mid-air (very cool)
* When hurling flasks of burning oil at a giant toad, a warrior aimed for the toad's open mouth to throw the oil down its gullet
* In a battle with enemies arrayed in a single-file line, a warrior hurled a javelin straight through the first enemy to spear it to the next opponent in line, entangling the one foe with the corpse of his ally
All the examples above were off-the-cuff maneuvers declared by players in-game at the moment of dice rolling (about half these examples came up in my games over the last two days).
At level 2, the warrior rolls d4 instead of d3. A roll of 3-4 on the d4, on an attack that beats AC overall, allows for a Mighty Deed of Arms.
At level 3, the warrior rolls d5 instead of d3. A roll of 3-5 on the d5, on an attack that beats AC overall, allows for a Mighty Deed of Arms.
And so on. It's fast, it's easy, it's ad hoc, and it allows for amazing in-game fighter maneuvers without the cumbersome elements of feats and prior edition attempts to do this. The rules do include DM guidelines on how to handle classic instances of Mighty Deeds (disarm, parry, bull rush, etc.) but in play so far almost every example I've seen is a really cool unique situation-specific maneuver - exactly what I am going for.
There are a couple other wrinkles, too. The "action die" (as I'm calling the d3, d4, d5, etc.) is also added to damage. (The same roll as for the attack -- if you get a 2 on the die for the attack, you add 2 to the damage.) Warriors with multiple weapons roll one action die and attach it to both weapon attack rolls. Etc.
Hopefully that makes sense. It's working out great in play so far.