Authoritarianism is a political system characterized by the rejection of political plurality, the use of strong central power to preserve the political status quo, and reductions in the rule of law, separation of powers, and democratic voting. Political scientists have created many typologies describing variations of authoritarian forms of government. Authoritarian regimes may be either autocratic or oligarchic and may be based upon the rule of a party or the military. States that have a blurred boundary between democracy and authoritarianism have some times been characterized as "hybrid democracies", "hybrid regimes" or "competitive authoritarian" states.

The political scientist Juan Linz, in an influential 1964 work, An Authoritarian Regime: Spain, defined authoritarianism as possessing four qualities:

Limited political pluralism, is realized with constraints on the legislature, political parties and interest groups.
Political legitimacy is based upon appeals to emotion and identification of the regime as a necessary evil to combat "easily recognizable societal problems, such as underdevelopment or insurgency."
Minimal political mobilization, and suppression of anti-regime activities.
Ill-defined executive powers, often vague and shifting extend the power of the executive.
Minimally defined, an authoritarian government lacks free and competitive direct elections to legislatures, free and competitive direct or indirect elections for executives, or both. Broadly defined, authoritarian states include countries that lack civil liberties such as freedom of religion, or countries in which the government and the opposition do not alternate in power at least once following free elections. Authoritarian states might contain nominally democratic institutions such as political parties, legislatures and elections which are managed to entrench authoritarian rule and can feature fraudulent, non-competitive elections. In contexts of democratic backsliding, scholars tend to identify authoritarian political leaders based on certain tactics, such as: politicizing independent institutions, spreading disinformation, aggrandizing executive power, quashing dissent, targeting vulnerable communities, stoking violence, and corrupting elections. Since 1946, the share of authoritarian states in the international political system increased until the mid-1970s but declined from then until the year 2000.
What are some defining qualities of authoritarianism?
1. Limited political pluralism or outright rejection of political pluralism.
2. Lack of civil liberties
3. Lack of free, fair and competitive elections
4. So-called democratic institutions corrupted by authoritarian rule
5. Use of election tactics such as spreading misinformation, politicizing independent institutions, quashing dissent, engaging in culture wars, targeting vulnerable communities, stoking violence, and aggrandizing executive power.
6. Use of a strong central power to preserve the political status quo at the cost of basic democratic ideals such as the rule of law, separation of powers, and voting rights.