The article analyses the functioning of the war-time Ukrainian humorous discourse in general and the cognitive mechanisms of humor, including the "Availability Heuristic" cognitive pattern in particular. The study aims to examine 12 Ukrainian war-time jokes and to reveal main cognitive patterns and accompanying stylistic figures producing the comic effect. All jokes manifest the application of the "Availability heuristic" cognitive pattern inherent to the war period when old pre-war realities are changed with new war-time realities and explained in a funny way. The study addresses some cognitive and pragmatic aspects of the war-time Ukrainian humor, focusing on the role of cognitive patterns in selecting stylistic humor devices, while processing the incoming information and shaping the cognitive frameworks of humor perception and creation. The paper reveals the main cognitive patterns, including the "Availability Heuristic," the "Distinct contrast," the "Negativity Thinking," the "Superiority or Illusionary Superiority," the "Easel," and their humorous actualization through such stylistic figures as paraprosdokian, irony, bathos, double entendre, pun, metaphor, and pastiche in its narrow meaning. The researched Ukrainian jokes are interwoven with the situational context of the dramatic events within the temporality of the speedy streaming news of the Russian-Ukrainian war. The paper explores the main pragmatic functions of Ukrainian war-time humorous discourse and makes additional remarks about a number of affirmations from some humor theories. Plain Language Summary: Cognitive patterns of Ukrainian wartime humor The article analyses cognitive, pragmatic and stylistic features of war-time Ukrainian Humorous discourse in general and the "Availability Heuristic" cognitive pattern in particular. The purpose of the research is to determine the role of this cognitive pattern in the creation of the comic effect in war-time verbal humor in Ukraine. The paper presents the results of the cognitive, pragmatic and stylistic analyses of twelve war-time Ukrainian jokes. The study determined that twelve researched jokes apply the "Availability Heuristic" cognitive pattern, which is characterized by solution search through pursuing fresh experience or information reflecting recent war events. It is accompanied by the "Distinct contrast" cognitive pattern, both of which are the manifestations of the incongruity mechanism. Besides, it is used together with the "Negativity Thinking" pattern, focusing on negative intensions, the cognitive "Easel" pattern, responsible for the dominance of visual pictures and images, and the cognitive pattern of "Superiority or Illusionary Superiority." All cognitive patterns have sets of stylistic figures standing behind it. In the researched jokes, the cognitive patterns are exhibited through paraprosdokian, irony, bathos, allusions, double entendre, puns, metaphors, pastiche in narrow meaning. The analyzed Ukrainian jokes are interwoven with the situational context of the dramatic events within a temporality of the speedy streaming news of the Russian-Ukrainian war. [ABSTRACT FROM AUTHOR]