Not quite 'fencing' or 'swashbuckling.' More like "sword-fighting where you have to do things more precise than just 'make an attack' and 'do damage.'"
What I kind of envision is a game going like this:
Allar has a scimitar and is wearing leather armor. Broman has a bastard sword and a shield, and is wearing chainmail.
Round one: Allar starts on the defensive, trying to get a read of his opponent's style. Broman aggressively attacks, but Allar manages to deflect and dodge.
Round two: Broman's overextended himself so he'll have a hard time defending, but he does have a shield protecting one side. Allar scrambles to attack from the opposite direction, and is fast enough to land a blow, but Broman's armor keeps it from doing any real harm. Broman continues to attack without taking any time to recover, so his attack is wild and Allar again manages to block it.
Round three: Knowing he can't easily get through Broman's armor, Allar feigns an opening. Broman obliges and goes all-out on an attack, leaving himself completely unable to defend. Allar blocks the attack but still strains under the force of the strike.
Round four: Broman has to take a moment to regain his balance. Allar steps inside Broman's reach and stabs upward with the tip of his scimitar. He could go for an easy jab to the gut, but he risks trying to get into Broman's armpit, where there's less armor. The attack hits and disable's Broman's sword arm.
Round five: Disarmed, Broman resorts to a clumsy grab with his shield arm, hoping to keep Allar from using his great maneuverability. Allar gets caught and scrambles to try to get out, since he can't effectively attack with his sword in a clinch, but he fails.
Round six: Broman knees Allar in the kidney a few times. Allar responds by drawing a knife with his off hand and slashing at Broman's side, but he only manages to slash Broman's thigh a bit, not deal any serious damage.
Round seven: Broman keeps kneeing Allar, and manages to stagger him with pain. Allar just reels and can't act.
Round eight: Broman shoves Allar away and awkwardly uses his crippled sword arm to undo the straps of his shield. Allar hacks at Broman, who chooses to block with his already injured arm, since another wound won't incapacitate him any more. The heavy chop cuts through the armor and completely debilitates Broman's sword arm.
Round nine: Broman ducks and grabs his dropped sword with his remaining arm. He can't parry yet, but he does manage to dodge well enough to keep Allar from getting through his armor again.
Round ten: Allar takes a moment to regain his footing and assess the situation. Broman does too, and they circle, trying to figure out what weakness of their opponent they can take advantage of.
Round eleven: Slow blood loss is weakening Broman, so he knows he can't wait. He puts everything he can into a heavy hack at Allar's leg, hoping to slow him down. Allar tries to step in close again and slip through Broman's armor to deliver a killing blow. Neither bothers with defense. Allar's leg gets slashed in half at the knee, but not before he manages to drive his sword into Broman's belly.
Round twelve: Broman starts to stagger away, hoping he can find someone to tend to him before he bleeds out. Allar lies on the ground, writhing, then passes out and probably dies.