Disadvantage

A disadvantage is an argument that states that something bad will happen if the affirmative's plan is passed. In this way, disadvantages are much like advantages, except that their results (impacts) are negative, rather than positive (hence the word "disadvantage".)

Structure
A properly constructed disadvantage need, at minimum, 3 elements to function properly:


 * Link: Establishes a connection between the plan and a result. It shows a cause-and-effect relationship; for example, if the plan was "go to McDonald's for dinner," the link might say "food from McDonald's is high in fat and sugar."


 * Impact: Shows that the result or effect of the plan (the thing that was linked) is undesirable. There may be multiple impacts for one link. For example, if the plan was linked to "eating food that is high in fat and sugar", the impacts might be "fatty and sugary foods lead to heart disease and diabetes" or "eating fatty and sugary foods once fosters an addiction to them."


 * Uniqueness: Shows that the link between the plan and the impact is unique to the Affirmative's plan, and is not happening already in the status quo. For example, if you already had diabetes and heart disease, then the disadvantage exists in the status quo and is not a reason to vote against the plan. Although uniqueness is a necessary element of a disadvantage, it is often only established implicitly when the disadvantage is first introduced.

In addition to the above, disadvantages commonly have other elements:


 * Brink: Shows that the status quo is at a tipping point, and so the impact (which might normally be harmless) is extremely harmful due to the context. A common analogy used to explain this is pushing a person: I were to push my friend, it wouldn't be that big of a deal; but if I were to push my friend while he was standing right on the edge of a cliff, he would fall to his death.


 * Internal links: Are sometimes necessary to establish extra "steps" between the plan and the the impact, which can strengthen or extend the main link. For example, an internal link to the McDonald's disadvantage might say that "foods higher in fat and sugar are addictive," strengthening the link to the second impact.

Weighing
In addition to running disadvantages, the Negative team must successfully weigh the disadvantages against the advantages of the plan, and attempt to show that the disadvantages matter more than the advantages. This is commonly referred to as impact calculus, and is a very important part of successfully using a disadvantage. Even if the Negative is also claiming that the plan has no advantages (solvency), they can still weigh the disadvantages as an either-or: "Even if their advantages exist, the disadvantages are still more important."

Utility
Disadvantages are very useful for the Negative, as they are "offensive" arguments that present the judge with a concrete reason why the plan is bad. Without disadvantages, the Negative can - at best - say that the effect of the plan will be completely neutral (e.g. if it has zero solvency). Disadvantages can thus be very persuasive, particularly when they have large impacts.

Defending against disadvantages
There are two basic ways to defend against a disadvantage: defeat the link, or defeat/mitigate the impact. Additionally, the Affirmative may turn the link or the impact. Disadvantages may also be defeated by challenging the uniqueness, brink, or any of the internal links.

Slippery slopes
When running disadvantages, it is easy to commit the slippery slope fallacy. For example, a Negative teams might string together several tenuous links to reach an obviously ridiculous impact. (A humorous example of this fallacy can be observed in this DirecTV advertisement.) In debate, slippery slope disadvantages often lead to nuclear war, although nuclear war is not the only possible slippery slope impact (and links to nuclear war may, at times, be legitimate.)

Slippery-slope disadvantages can be exceedingly enjoyable to run, but are usually a poor strategic choice. Even if the Negative technically defends all the links, judges will often vote against such a disadvantage because it seems ridiculous.