ABox

ABox
ABox is name for a table with 16 fields sorted into 4 rows, 4 columns and 4 sections (called A-squares). Each field in ABox  is marked by a letter. On one hand ABox is the simplest game presented on this website on the other hand it is a game that has infinitely many solutions (compare with other games presented on this website).
A goal of the game is to replace 16 letters in ABox by 16 natural numbers that comply with the Rule for Four Numbers.

The Rule for Four Numbers
The rule tells that 16 letters in ABox must be replaced by 16 natural numbers in such way that the sum of four numbers in any row, in any column and also in any section (A-square) was always the same (see picture below).

The game has lots of variants having additional rules

For example: more than a half of 16 numbers must be different, among numbers cannot be zero, 2 same numbers are not allowed, among numbers have to be at least 2 same numbers or among 16 numbers must be number 1.

Tips for players!
Look at the Law of Attraction in menu Two - Two Laws.
Read the book Magická nula a cesty čísel (The Magical Zero and Ways of Numbers) by Dark M. Horse.

Another examples: