The parliament is made up of 129 elected MSPs, elected by the additional member system, a form of proportional representation. Elections are normally held every four years on the first Thursday in May. Anyone who can stand for election to the House of Commons may stand for election to the parliament. Peers may also stand.
Each voter has two votes – one for a constituency and one for a member from a regional list.
For the first vote, Scotland is divided into 73 single member constituencies, which are the same as those for UK general elections. Voting is the same as in UK general elections using the first-past-the-post system in which the candidate with the most votes, though not necessarily the majority of votes, is returned as an MSP.
The second vote is more complicated. Scotland is split into eight regions – Highlands & Islands, North East Scotland, Mid Scotland & Fife, West of Scotland, Central Scotland, Glasgow, Lothians and South of Scotland. Each region returns seven MSPs. Before the election each political party chooses a list of candidates for each region. A candidate in a single member constituency can be on a party's list for a region. Candidates on a party's regional list are arranged in the party's order of preference, with the candidate that the party would most like to see elected placed first.
In the second vote, votes are cast for parties. The number of MSPs returned for each party in each region is shared out in proportion to the share of the vote received by each party. If a candidate on a party's list has already been returned in a single member constituency, the next candidate on the list is successful. Parties use this 'closed' list system as a form of insurance policy to ensure that key candidates have a better chance of becoming an MSP.
If a constituency member resigns or dies, then a by-election is held. If a regional member resigns or dies then the vacant seat is taken by the next person on the regional list for that party.
The Queen officially opens the parliament after each election but her address is not a 'Queen's speech' in the Westminster sense – the first minister outlines the legislative programme in a speech to parliament. A presiding officer is elected by MSPs at the first meeting after an election.
The first elections to the parliament were held on May 6th 1999. Further elections were held on May 1st 2003. The first meeting of the parliament was on May 12th 1999. The Queen officially opened the parliament for the first time on July 1st 1999.