Most voting systems are based on the idea that the minority obeys the majority. Usually, if a plan is supported by more than half of the voters, it will be passed. However, when there are more than two options to choose from, either option may not be supported by more than half, and different voting systems will produce different results. Therefore, which voting system is adopted has an important influence on the election results.
The voting system will specify the form of the "ballot" and the algorithm for calculating the voting result. The result of voting may be that a single candidate wins, or many people win, such as the election of the legislature. The voting system will also show how voters' voting rights are distributed and how voters are allocated to independent constituencies.
The actual operation of the election is usually not the concern of the voting system. The voting system does not specify whether the votes are paper, punch cards or electronic. The voting system will not stipulate how to protect the privacy of voters, how to count votes correctly, or who has the right to vote. These belong to the research scope of a broader election or electoral system. Different voting systems have different voting forms. In the sequential voting system, like the ranking check system and the Bolda counting method, voters rank the options according to their support. In the interval voting system, voters score each option. In the majority vote system (also known as the "first past the post system"), voters can only choose one; In the approved voting system, voters can choose any candidate project; In the voting system, voters can circle multiple candidates on the ballot. Among them, the number of items that can be circled can be set according to the feelings of different people. In the cumulative electoral system, voters can cast many votes for the same candidate.
Other voting systems have other arrangements for votes, for example, voters can write down the names of candidates, or voters can veto all options (if established, the election must be re-conducted from the nomination stage). Many elections are held under the concept of "one person, one vote", that is, every voter's vote has the same value. But in company elections, for example, the value of votes is usually calculated according to the company shares held by voters and becomes "one share, one vote".
In some elections, the value of votes depends on the status of voters. Under special circumstances, if the votes are equal, one voter has the right to cast another vote to decide the result. Voters with this privilege may not have the right to vote at first. For example, in the United States Senate, the vice president of the United States usually does not have the right to vote, and can only vote when the number of votes in the parliament is equal. Therefore, the value of his vote is actually not as good as that of ordinary votes.
The weight of votes is different from that of mobilization votes, because people do not necessarily act independently, but often organize themselves to vote together. A highly mobilized voting group whose members vote almost unanimously (such as political parties in parliament) is enough to change the election results. The political parties in parliament will form an alliance to increase their influence. Many voting systems require stricter conditions than majority voting. For example, changing the status quo requires an absolute majority. The most extreme example is the system that needs unanimous adoption. If the purpose of voting is to decide whether to accept new members, then the ballot that refuses new members to join is called a "black ball".
Another mechanism to change the status quo requires the number of voters to meet the statutory minimum requirements. Usually a quorum refers to the number of people voting, not the number of people voting. However, this system often encourages opponents to prevent meetings from reaching a quorum by refusing to vote. Elections are usually held to elect more than one member of the legislature. The election may not be divided into constituencies, or representatives may be elected by their respective constituencies.
Countries such as Israel adopt a single constituency system to elect the entire parliament. Ireland and Belgium divide the country into many small constituencies. The United States and Britain adopt a single winner system. Some adopt the system of single constituency and two votes, while others divide small areas into large constituencies.
The way constituencies are divided and seats are allocated may greatly change the election results. According to the population data obtained from the census, the number of seats in the constituency will be redistributed. Redefining a constituency means readjusting the boundaries of the constituency. Both of these processes may change the election results, so they are highly controversial in politics. Sometimes it may be manipulated by politics, resulting in unfair constituency division. This is called unfair constituency division.