Rules of order, also known as standing orders or rules of procedure, are the written rules of parliamentary procedure adopted by a deliberative body, which detail the processes used by the body to make decisions. Some bodies rely more on precedent and on the judgment of the presiding officer, whereas others rely more heavily on the written rules.
Rules of order consist of rules written by the body itself, but also usually supplemented by a published parliamentary authority adopted by the body. Typically, national, state, and other full-scale legislative assemblies have extensive internally written rules of order, whereas non-legislative bodies write and adopt a limited set of specific rules as the need arises.
Parliamentary procedure in most western democracies have its roots in the procedures used to conduct business in the British Parliament. It is a process used to conduct face to face meetings. In practice, it works best in groups of a dozen or so or more (smaller groups usually manage their meetings informally) and less than a thousand or so (larger groups sometimes manage their meetings via parliamentary procedure, but in practice, such meetings must be tightly managed and ruled by an agenda determined in advance to function).
Both House of Congress in the United States have their own distinctive rules of parliamentary procedure. Both follow a practice of immediately assigning all new legislation to one or more committees (absent bipartisan agreement) which in turn, typically refer new legislation to a subcommittee. Once a bill has cleared all subcommittees and committees to which it is assigned it is then ready for consideration before the entire House.
In the House of Representatives, the agenda is tightly controlled by the majority members of the House Rules Committee (which is therefore one of the most powerful in Congress, because it has defacto veto power over all legislation and proposed amendments through its power to prevent them from being considered) and almost all matters (except proposed constitutional amendments and veto overrides which call for two-thirds majority support) are decided by a majority vote. The House has to readopt new rules every two years.
In the U.S. Senate, there is a rules committee, but it is far less powerful. Any single member of the Senate may debate any issue that comes before the Senate for an unlimited length of time in what is called a filibuster, until 60 Senators agree to a "clouture" vote to end debate. This has the effect of creating a de facto 60% majority rule for all matters in the Senate except constitutional amendments, veto overrides and treaties (which require two-thirds majority support). The U.S. Senate also has a system of "holds" which permit Senators to prevent consideration of Presidential nominations until their concerns are addressed, subject to relatively few limitations. As a result, the U.S. Senate tends to be more bipartisan in approach to legislation. Even when, as is the case prior to the 2004 election, one party controls both the Presidency and both Houses of Congress, the parliamentary procedures that apply in the Senate give the minority a vote right if it can unite 41 Senators in opposition to a proposal.
Most state legislatures follow rules more like the U.S. House of Representatives, than those of the U.S. Senate and are based on Mason's Manual of Legislative Procedure.
The rules of procedure adopted by most other deliberative assemblies is Robert's Rules of Order. US organizations dedicated to promoting the general use of parliamentary procedure include the National Association of Parliamentarians and the American Institute of Parliamentarians.
Most civic groups (churches, non-profit organizations, and for profit corporations holding shareholder's meetings) conduct their meetings in accordance with some version or derivative of Robert's Rules of Order. This generally provides for majority rule, except to change the rules which generally requires a two-thirds majority. Under Robert's Rules of Order, only one matter may be considered at any one time. Typically a "motion" is proposed, amendments to the motion are proposed, debated and voted upon one by one, and the final motion, as amendment is then voted upon. Debaters must be recognized by a facilitator to speak. Typically this is conducted concerning several matters set forth in advance in an agenda. At its best, Robert's Rules of Order, provides an orderly framework in which a large number of people to each have their say and participate fully in the crafting a resolutions to be adopted by the entire group. At its worse, the complexity of the Rules allows those who understand the Rules to take advantage of those who do not. Even when the Rules are perfectly understood by all participants, the Rules, by their nature, are path dependent. The ultimate outcome of the process often depends upon the order in which issues are considered given a particular group of people with a particular set of preferences. Furthermore, the Rules can be a cumbersome way to deal with complex subjects -- giving everyone in a large room full of people a full say on every issue can take a great deal of time.
A number of other methods of conducting meetings with large numbers of people exist, although most have only niche followings.
Quaker Meetings are far less formally mediated, with individuals essentially speaking "as the spirit moves them", and are oriented towards consensus solutions with a secretary of the meeting charged with digesting all that is said at a meeting and finding within its deliberations points of common ground.
Feminist Process places particular emphasis on who gets to speak when, using what is called an "affirmative stack" to give priority to those who speak infrequently, and also seeks to be less hierarchical than traditional Robert's Rules of Order meetings where the facilitiator basically "rules" the meeting.
The concept of "approval voting" while not terribly successul in a general election context, can be used with considerable success in a parliamentary context where social norms limit the use of strategic voting techniques. In approval voting, the body considers not just a single proposal at a time, but many proposals (some of which may be variations on a theme) and generally uses multiple proposals in place of amendments (unless all supporters of a proposal abandon the original form). After all proposals for dealing which a situation are made and debated, the members of the group vote for every proposal that they can "live with" and the proposal with the most support wins. Approval voting has the virtues of being both sequence independent (the order in which proposals are made doesn't affect the outcome) and of favoring proposals with the broadest support, instead of simply favoring the first proposal to receive majority support. But, approval voting has the potential to be abused if a member of the group votes only for a favorite proposal, instead of actually voting for any propose that the member can "live with."
Often participants in a meeting will short circuit the parliamentary process by taking a "straw poll" (i.e. a non-binding expression of opinion), to see if a proposal or amendment with strong support by a few vocal proponents is succeptible to being approved by the larger group, or will be defeated regardless of the arguments made. The U.S. Supreme Court uses a straw poll method to assign initial responsibility for drafting opinions in the cases which it decides.