A construction set, comprising: at least three types of construction elements, implemented with an ability to connect to with each other one another and form a single construction, wherein construction elements (10, 19, 20, 28, 31) of a first type, contain a base, made flat and having rectangular form, sides having length in multiples of «a», and an interlocking joint, created by positioning protrusions (2, 3, 4, 6, 7, 11, 12, 13, 14, 15, 16, 17, 18, 21, 22, 23, 24, 25, 26, 29, 30) on the base, forming four groups A, wherein a first group A has protrusions, positioned, at least, on one side of the base, with height greater than «0.5a», but not more than «a», made with a cross-shaped cross-section, where a distance between opposing ends of the cross is equal to «a», and/or made tubular, having a ring-shaped cross-section with an outer diameter equal to «a», a second group A has protrusions positioned on at least one side of the base, with a height equal to «0.5a», made tubular, with cross-sections in a form of square having side length in the tubular protrusion equal to «a», a third group A has protrusions, made in a form of rectangular plates, positioned with its midline on ends of the base, flush with these ends, having, along short sides, ledges, with width equal to «a», protruding not more than «0.5a» from the base ends, angled towards each other with a gap formed between their end parts no greater than «a», a fourth group A has protrusions made in a form of corners, having shelves positioned perpendicular to planes of the base on its adjacent ends, flush with these ends, having length equal to «a», width not greater than «0.5a», wherein all protrusions (2, 3, 4, 6, 7, 11, 12, 13, 14, 15, 16, 17, 18, 21, 22, 23, 24, 25, 26, 29, 30) are positioned on the base in accordance with a coordinate grid of mutually perpendicular lines parallel to base edges, wherein a distance between neighboring lines on the coordinate grid equal to «2a», a distance between edges and neighboring lines on the coordinate grid is equal to «0.5a», wherein the protrusions of the first group A are positioned at points where coordinate grid lines intersect, the protrusions of the second group A are at points where the diagonals of the cells of the coordinate grid intersect, the protrusions of the third group A are in a middle between neighboring protrusions of the first group A that are positioned flush with the ends of the base, the protrusions of the fourth group A are at corners of the base, wherein, during implementation of the protrusions with the cross-shaped cross-section of the first group A, the end parts are flush with the base ends; construction elements (9,27,32) of a second type contain a base, made flat and having rectangular form, at least one side with length equal to «a», the other is a multiple of «a», and an interlocking joint, created by positioning protrusions on the base, forming three groups B, wherein the first group B has protrusions, positioned, at least, on one side of the base, with a height greater than «0.5a», but not more than «a», made with a cross-shaped cross-section, where a distance between opposing ends of the cross is equal to «a», and/or made tubular, having a ring-shaped cross-section with an outer diameter equal to «a», a second group A has protrusions, made in a form of rectangular plates, positioned with its midline on the ends of the base, flush with these ends, having, along the short sides, ledges, with width equal to «a», protruding not more than «0.5a» from the base ends, angled towards each other with a gap formed between their end parts no greater than «a», a third group B has protrusions made in a form of corners, having shelves positioned perpendicular to the planes of the base on its adjacent ends, flush with these ends, having length equal to «a», width not greater than «0.5a», wherein all protrusions (2, 3, 4, 6, 7, 11, 12, 13, 14, 15, 16, 17, 18, 21, 22, 23, 24, 25, 26, 29, 30) are positioned on the base in accordance with a coordinate grid of mutually perpendicular lines parallel to base edges, wherein a distance between neighboring lines on the coordinate grid is equal to «2a», a distance between edges and neighboring lines on the coordinate grid is equal to «0.5a, wherein the protrusions of the first group B of the second element type are positioned at points where coordinate grid lines intersect, the protrusions of the second group B are in the middle between neighboring the protrusions of the first group B that are positioned flush with the ends of the base, the protrusions of the third group B are at the corners of the base, wherein, during implementation of the protrusions with the cross-shaped cross-section of the first group B, the end parts are flush with the base end, wherein, elements of the first and/or second type have protrusions (2, 3, 4, 6, 7, 11, 12, 13, 14, 15, 16, 17, 18, 21, 22, 23, 24, 25, 26, 29, 30) with the ring-shaped cross-sections of the first group B implemented with grooves on an inner side; construction elements of a third type are made tubular and/or rod-shaped and are equipped with, at least, one protrusion on a side surface with an ability to longitudinally move construction elements of the third type into the protrusions with the ring-shaped cross-section when placing the protrusions of the construction elements of the third type into grooves of protrusions with the ring-shaped cross-section.