Icosahedral Die

Icosahedral Number

Icosahedron

Icosian Game

Icosidodecahedron

Imperfect Information

Imperfect Square

Imperfect Rectangle

Impossible Figure

Impossible Problem

Impossible Tribar

Indecidable Figure

Indicator

Indian Method

Indian Mill

Induction

Inextensible Latin Square

Inextricable Maze

Inferential Problem

Inferential Recreation

Infinite Game

Information

Inheritance

Initial Position

Instant Insanity

Insulation

Integer

Intelligence Test

Interactive Game

Intermediary Square

Intruder

Invariant Number

Inversion

Irma

Isometric Paper

Isomorphic Games

Isomorphic Lattice

Isomorphic Recreation

Isosceles Triangle

Iteration

Jacob Scale

Jacquet

Jaina Square

Japanese Crystal

Japanese Morpion

Je-kim

Jealous Husbands

Jealousy Multiplication

Jerusalem Cross

Jigsaw

Joker

Josephus Stratagem

Jourdain Card

Jump

Jumper

K-gonal Number

Kakuro

Kakutani's Problem

Kaleidocycle

Kaliningrad Bridges

Kaprekar Number

Kaprekar Routine

Keith-Craver Formula

Key

Keyword

Kharujaho Square

King

Kirkman Block

Kirkman Schoolgirls

Kite

Klein Bottle

Klein Torus

Knave

Knight

Knight's Corners

Knight's Path

Knight's Tour

Knot

Koch Antisnowflake

Koch Curve

Koch Island

Koch Snowflake

Konigsberg Bridges

Kordiemsky Triangle

Kowa Magic Circles

Kraitchik Formula