This guide is for forming Italy for newer to moderate players. We will explain one guide for Italy. This is for the Vanilla version of the game, so no mods. Alright bois, buckle up and lets roll out!
How to Form Italy (Step-by-Step)
Step 1: Choosing a Nation
There are many nations in Italy. All of them can form Italy if you play them correctly. But since we are new to the game or we have moderate experience lets go cut it down to the two easiest ones. The first one is Sardinia-Piedmont and the second is Two Sicilies. They both have pros and cons. The pros of Sardinia-Piedmont is that they can easily ally France with little to no effort. They start with some decisions to help them reach Great Power status and are right next to Austria which we might need to attack sooner or later. Also, they get a gold RGO on Sardinia early in the game. The cons of Sardinia-Piedmont is that they have lower population so a smaller army and start with a very small navy. Also, Sardinia-Piedmont is weaker than Two Sicilies who can beat the Sardinians to Great Power status. The pros of Two Sicilies is that they have more population than Sardinia. Also, they start with a bigger army and navy. This means you can out gun the Sardinians. The cons though are Two Sicilies doensn't have those decisions I was talking about. Also, Two Sicilies might have a hard time finding a Great Power ally to help them conquest Italy and also they are far away from Austria which you might need to fight. The best choice is Sardinia-Piedmont. They can grow really fast and can become Great Power pretty quick depending on how you play. So we will pick them and move on.
Step 2: Alliances and Targets
So, at the start of the game, Austria and France start friendly with you. Austria 99% of the time won't try to sphere so it might take a bit but France will soon sphere you, which means you can easily make an alliance with him. Now, you must strike. Build up your army until you have at least one full army of your desired army composition. Then strike at the Austrians. You want to justify an acquire state war goal on the Austrians. Once it is complete and you are ready then declare on the Austrians for Lombardia. I would say to defend until the French arrive, you won't be able to push without the French. Once the French arrive then push with them. Do not lead the French, stay behind and reinforce battles with the French. This war should be your only war in forming Italy this way. Now, after you win the war against Austria that is it. Now, here comes the fun part. Becoming a Great Power. There are many ways to become a Great Power, but the #1 way to become GP (Great Power) is to get prestige. This is why I said Sardinia was better. They have a decision called, "Cavour's Diplomacy" which gives France Nice, and the Savoy region for -10 infamy and 20 prestige. This is big. Now, if you haven't started already, start researching the prestige techs. This is in the culture tab and on the very left side. Those techs are your prestige techs that you want to research. It might take a while but soon you will become Great Power.
Step 3: Great Power and Spheres
After becoming a Great Power, you want to immediately want to start sphering Italian minors. I recommend starting with the closest Italian minors to you. So like Modena. You are going to have to fight France and mainly Austria for control of these guys. But it is worth it. Once you get one, move onto the next one and keeping going down the list until you reach Two Sicilies. There are two things that might happen. #1 Two Sicilies might become a GP or #2 Two Sicilies might not have. You want #2. If Two Sicilies becomes GP then you have to knock them down which will require a war against them. If you have to fight them then just use your allies, don't call in France until you absolutely need it. If you call in France, they will peace out with Two Sicilies before they fall out of GP. To knock them out of GP, you just have to occupy their country until they drop to #9. Make sure you do a humiliate war goal. Now, when they drop, you want to add the "Add To Sphere" war goal. This will make Two Sicilies part of your sphere. Well there you go. Now, you can form Italy.