This is the word you will hear thrown around most often in debating. A case is the motion that the government team has put forward for debate. The case will define the topic of debate, it's place and time and the actors involved. The government has a responsibility to define all of these things (known as 'defining the debate') as clearly as possible. A case can be a moral judgement or a detailed plan, or somewhere in between. An example of a moral judgment or 'principled' case is: Be it resolved that (BIRT) this House believes that pre-emtpive war is wrong. An example of a plan or 'model' case is: BIRT the United States should ratify the Kyoto Protocol. You can see that the plan case calls for a specific course of action, whereas the principled case merely takes an ethical stance on one side or another of a particular issue. Both types of cases are equally valid.
Open and Closed Motions
As a matter of formal parliamentary procedure, there must always be an 'official' motion before the house. At a tournament, the tournament director (TD) will give the debaters the motion for each round of debate. These motions can be open or closed. This will be announced before the debate begins. Most tournaments will use only one or the other type of motion, although some tournaments will mix and match. A closed motion (also known as a 'straight' or 'tight-link' motion) is one where the government team must use the motion given as the basis for it's case. Sometimes the motion will be very narrow, and the government team will have nothing to do but come up with arguments. For example: BIRT Canada should completely ban the sale and manufacture and consumption of cigarettes. There is no margin for maneuvre here at all. However, other times the motion will be less strictly defined, and the government team will have some latitude as to how it interprets it. For example: BIRT The world should intervene in the Sudan. Here, the government team will have to explain what it means by 'world' and 'intervene'. Does 'world' mean the UN, or Nato, or the African Union, or the EU? Does 'intervene' mean invasion, diplomatic sanctions, economic sanctions, etc. An open motion (also known as a 'squirrellable' motion) is one where the TD is merely respecting the formalities of parliamentary debate, but intends to leave it up entirely to the government team what the debate shall be about. They are usually silly, or will follow some theme for the tournament. For example: This House would dance with the devil by the pale moonlight. With an open motion, the government team is expected to provide its own case for debate. These cases will usually be prepared beforehand. (Erik Eastaugh, Debates, Cases, Arguments, Evidence and Assertions-- the Jargon Explained.)