Alexei Rykov in the context of Chairman

The Right Opposition (Russian: Правая оппозиция, romanized: Pravaya oppozitsiya) or Right Tendency (Правый уклон, Praviy uklon) in the All-Union Communist Party (Bolsheviks) was a label formulated by Joseph Stalin in Autumn of 1928 for the opposition against certain measures included within the first five-year plan, an opposition which was led by Nikolai Bukharin, Alexei Rykov, Mikhail Tomsky, and their supporters within the Soviet Union that did not follow the so-called "general line of the party". It is also the name given to "right-wing" critics within the Communist movement internationally, particularly those who coalesced in the International Communist Opposition, regardless of whether they identified with Bukharin and Rykov.

The Case of the Anti-Soviet "Bloc of Rightists and Trotskyites" (or "Bloc of Rights and Trotskyites"; Russian: Процесс антисоветского «право-троцкистского блока»), also known as the Trial of the Twenty-One, was the last of the three public Moscow trials charging prominent Bolsheviks with espionage and treason. The Trial of the Twenty-One took place in Moscow in March 1938, towards the end of the Soviet Great Purge. The accused were tortured to extract confessions and publicly admitted their guilt during the show trial. Most of the accused, including Nikolai Bukharin, Alexei Rykov and Genrikh Yagoda, were convicted, and sentenced to death. All charges are considered fabricated except the against NKVD chief Genrikh Yagoda of poisoning Valerian Kuybyshev, Vyacheslav Menzhinsky, and Maxim Gorky; Yagoda might indeed have conducted the poisoning with the assistance of "Kremlin's doctors" Pletnyov and Lev Levin, but they did it on the orders from Stalin himself.

The Left Communists (Russian: левые коммунисты, levyye kommunisty) or Left Bolsheviks (левые большевики, levyye bolsheviki) were a faction of the Russian Communist Party (Bolsheviks) who were at their most prominent in December 1917 and early 1918, during the debates on signing a separate peace with the Central Powers of World War I. The Left Communist faction opposed a peace on the terms of the Treaty of Brest-Litovsk, and instead advocated a "revolutionary war" to foment revolution in Germany and across Europe. The faction also held radical left-wing positions on economic and social policies, including support for more workers' control and a more democratic military, and supported internationalism to the point of rejecting the idea of national self-determination, particularly in the form of an independent Poland. The faction was led by Nikolai Bukharin, and included Andrei Bubnov, Alexandra Kollontai, Valerian Osinsky, Georgy Pyatakov, Yevgeni Preobrazhensky, Karl Radek, Vladimir Smirnov and Varvara Yakovleva. Their support was strong in the party's Moscow bureau and in Petrograd.

At the Seventh Party Congress (6–8 March 1918), which had been packed with supporters of the peace by Vladimir Lenin and Yakov Sverdlov, the Left Communists abstained from the vote calling for ratification of the Treaty of Brest-Litovsk (3 March 1918). They abandoned their advocacy of "revolutionary war", but in their journal Kommunist (published in four issues in Moscow in April–June 1918) criticized the "pragmatism" and "conservatism" of Lenin and his allies, urging immediate nationalization of industry, workers' control, and no compromise with capitalist forces, domestic or foreign. Left Communists were dominant in Vesenkha for four months, from December 1917 to April 1918, with Osinsky as the head of Vesenkha for three months, followed by Yakovleva as head for one month. Left Communists were then replaced by moderates such as Alexei Rykov, Vladimir Milyutin, and Yuri Larin, in the period from April 1918 up to 1921.