> An Eisen Krieger wants to convince a lazy, vanitous and glutonous Montaigne Duke to lower taxes on common people and to better their situation. The player makes and incredible performance, with lot of measured words, trying to convince him that more happy and educated people gives more money and he will be a pig smelling like roses (not exactly that words... but the concept).

> In another RPG, this would be an Opposed Roll. But in this game I haven't seen something like "opposed rolls". So I return to the basics stated on the red box on page 169 of the core rules: decide how to roll, decide consequences and oportunities, and use raises to change the scene.

> I decide the player to roll Panache + Convince, and give him an extra dice for his interpretation. 

> I tell him that there are 3 consequences: 1) The Duke is horrified by the simple fact of treating common people as something more than rabble. 2) The Duke takes notice that you want to bribe him using his vanity and gets angry. 3) A sycophant listens the conversation.

Sounds good.  Depending on the scores, I'd probably try to include one more consequence and one or two opportunities.  Unless the player has ideas.  But what is at stake in the scene?  If the Duke doesn't acquiesce to the Krieger's bribe, what does the hero stand to lose?  Because THAT is the real risk.

> The players tell me if it is possible to make the Duke think it has been the Duke's idea. I find this interesting and accept it, so I tag it as an Opportunity.

Yup.  Perfect.

> So he rolls and scores 4 raises. He uses 3 raises to cancel the consequences and 1 to take the oportunity. So... I supose the roll is succesfull and he implants the Duke the idea of educated and clean people working hard and giving him money happily and the other Dukes having envy of him.

Not quite.  You need 1 raise to accomplish intent.  So 1 raise bribes the duke.  So that leaves the player with 3 raises.  He can buy off all of the consequences and leave the opportunity, or suffer one of the consequences to take the opportunity.

> My question is. Have I made it well? I mean. The rules are like that, or I had to simply make an opossed roll of Convince VS Empathy?

You've done it well.  Though if you really want to get into the weeds, here are the things you need to ask yourself:

• What is at risk in the scene?
• Is there a villain manipulating things behind the scenes?
• Is the duke a villain?  How does this request jive with his current scheme?

Here's the deal—it REALLY depends what is at risk in the scene or story.  If nothing is at risk, you can just let the player succeed and be done with it.  Move on.  Not every scene needs a Risk.  Also, what does the duke want?  Let's take a look at your scenario again:

An Eisen Krieger wants to convince a lazy, vanitous and glutonous Montaigne Duke to lower taxes on common people and to better their situation.

• All three of your consequences are fine, but might be a bit short sighted.
• The Duke accepts your bribe but expects a favor in return.
• The Duke's generosity causes him to lose face with his peers — unless certain conditions are met.
• The Duke's tax easement is far too modest to provide any real aid.
• An ally of the duke is actually a villain who is trying to sow an uprising among the pesantry, but the duke is so far ignorant of this.
• A local rabblerouser has become something of a folk hero for raiding the duke's tax collectors, and is not eager to give up his newfound fame.
• The duke is actually deep in dept to the sovereign, and lowering taxes is going to make him short on his expected payment.  Lucky for you, the duke has poor math skills.  However...
• Too late, the uprising has already begun.

Now, most of these the players wouldn't know, but could be spun into more consequences and opportunities if you need them.