The Big City has two houses; the Alrania which elects the Prime Minister and the President (is re-elected every 10 years) and the District Council which is re-elected every 5 years.
The best thing for any political party in Big City is a majority in the Alrania which allows them to form the government and chose the Prime Minister and the President of the country but, the District Council allows political parties to exercise power in certain states. In Big City, the general elections decide that who controls the state, if one party wins more than half of the seats from a specific state, they get considerable autonomy but if they get the maximum number of seats but not the majority then, they get some control in the state but the Center still has more power and the final say in the decisions made in the state. So, the District Council Elections are held along with the general elections once and then after 5 years they are held separately once again. This means that the central government in Big City changes every 10 years but the state government changes every 5 years.
This system of holding District Council Elections after every 5 years was introduced after the 2010 elections and the first independent District Council Elections were held in 2015. There is one unique rule in the independent District Council Elections which affects the central government that is, if another party apart from the one in power at the center manages to get a majority in all the five states, then re-elections are held for the Alrania too. Though, this has never happened in Big City but it came very close to happening in 2045 when the Peace Party held the powers in the central government and the Goggle Party got a majority in four states out of the five.