World of Fallout 4

The world of Fallout 4 has many differences to its real life gaming counterpart.

Central Mass

 * Devens - Fort Devens, commonly called Devens, is the Brigadiers of the Worcester Coalition's main military base. It houses hundreds of soldiers and reserves as the Coalition campaigns east.
 * Worcester - Incorrectly pronounced as War-ses-ter, Worcester is the capital of the Worcester Coalition. It is a large town, perhaps the most diverse in the Commonwealth.

Middlesex

 * Lex - Formely Lexington, Lex is among the wealthiest towns in the Commonwealth, though also the most arrogant. Ruled by the Council of Merchants, the head of the merchant families of Lex, they see themsleves as the leaders of the Middlesex area. The city prefers to use mercenary companies rather than their own soldiers to fight wars. They have strong-armed Spy Pond into a trade alliance and essentially vassalization, and start the game attempting to due the same to Tanner. They are the largest buyer of slaves in the region, to use on their massive farms.
 * Natick - The home of the second largest faction in the Western Coaliton, the Red Hawks, a large band of raiders. The Brigadiers and Phillip Monroe defeated them and occupied the mall, leading to the remaining Hawks to swear fealty. The Hawks rebuilt in strength, and their members are still raiders - though they only raid areas allowed by the Coalition.
 * Sanctuary - Sanctuary, formerly Sanctuary Hills, was a small trading center. Its location along Route 9 made it a hub for traders. At the start of Fallout 4 it is sacked by the Western Coalition.
 * Spy Pond - Formerly Arlington, Spy Pond is a small settlement located on the shores of its namesake. Its economy is based around trade due to its location on the way to the Boston area. It was protected by the mercenary company called the Sachems, until Lex paid the Sachems into opening the gates of the settlement. Spy Pond is now under Lex's control as part of their "trade alliance".
 * Tanner - Formerly Woburn, Tanner was founded by a historian who discovered that the city was once home to many tanneries and factories. The town now bases its economy on Brahmin farming and tanning. They start the game at war with Lex, who is attempting to annex the town to take over its industry.
 * The Low - Formerly Lowell, The Low is a large town and is the industrial center of the Commonwealth. Many of the Pre-War factories and mills were restored by the time of the game. Several trade companies, the largest being the Millers, have factories and offices in The Low.

Boston

 * Boston Airport - Once in ruins, the Airport was quickly restored by the Brotherhood of Steel in order to secure a steady income of supplies. All caravans are welcome, though caravans need to take care not to bring energy weapons or other high level technology that would be confiscated by the Brotherhood. Trade is slow, though there is a good amount of trade with Orient.
 * Diamond City - The largest city in the Commonwealth and the capital of the Massachusetts Bay Confederation. Pre-War, it was the baseball stadium for the Boston team. The large walls of the stadium made for great defenses, allowing the city to prosper.
 * Orient - Formely Oriental Hights in East Boston, Orient is a member of the MBC. Lately, with the threat of the Coalition and its own issues, Orient has considered leaving the MBC, potentially joining the Brotherhood of Steel.
 * Southie - Formerly South Boston, Southie is located on the easily defended Dorchester Heights. Southie is a member of MBC, and near the end of the game is sacked by the invading Bnrit'sh.

Norfolk

 * Quincy - Quincy is the largest city in Norfolk, and the capital for the Gunner raiding gang, who took over the city using violent methods. From Quincy the Gunners launch raids into Boston.
 * The Big Dud - The Chinese megaton nuke aimed at CIT proved to be ineffective, as incorrecting targeting leading to it striking south in Brookline, and not even going off. The massive warhead was discovered by Children of the Atom missionaries, and is now "their Jerusalem, their Mecca." It is the main base of the religion.

Brotherhood of Steel
The Brotherhood of Steel is led by the young Arthur Maxson, who leads the Brotherhood aboard the Prydwen - a massive airship. The BoS make their base in the former Boston Airport. They are on a crusade to restore the Commonwealth to its glory - with Maxson believing he is the chosen Patriot. They are incredibly well-armed and well-equipped, but they are distrusted by most of the population due to their sudden arrival.

Massachusetts Bay Confederation
The MBC is a confederation of several settlements in the Commonwealth, similar to the NCR of the west, except much weaker. Their capital is Diamond City, the largest city in the Commonwealth. Other settlements include Orient (Orient Hights, East Boston), Beacon Hill, Bunker Hill, and Southie. The MBC's goal is to expand into the former suburbs of Boston, with settlements like Lex and Spy Pond being considered for membership.

Gunners
The Gunners are a large gang of raiders that conquered the ruins of Quincy. From Quincy, the raiders launch raids and attacks across Norfolk, and large groups sometimes head into Boston and threaten Southie.

Millers
The Millers are a company based in the ruins of Lowell, now simply known as The Low. They make firearms and ammunition for the factions across the Commonwealth. The customer doesn't matter as long as they are willing to pay.

Minutemen
The Minutemen are an army loyal "to the Commonwealth". Based in Diamond City, they protect the trails, roads, and highways from raiders. They are also paid by the cities for defense, though they refuse to partake in offensive actions, leading to a splinter faction heading to Lex to aid in their war.

Worcester Coalition
Commonly referred to as the Coalition, the Coalition is a massive "alliance" of settlers, mercenaries, traders, and raiders under the autocratic rule of High Colonel Phillip Monroe. They start the game campaigning east, with the ultimate goal of defeating the MBC and conquering the Commonwealth.