C :: Boolean Value Cross-functional In Game TicTacToe

Why something doesn't work without setting global variables. I want to know how to deliver values for example my boolean value "ende" (means end) from the function in line 99

Code:
bool pruefeGewinn() or in line 116 Code: bool spielfeldVoll() to the main function for using it there for Code: } while (ende != true); in line 164.

How to return it correctly?

Here is the Code of the game TicTacToe.

Code:
#include <stdio.h> // In- and Output
#include <stdlib.h> // Implementation of many functions
#include <stdbool.h> // Allows in C99 True and False as Boolean
#include <time.h> // Allows using Random by time

/*----------------------- Constants -------------------------*/

#define KANTENLAENGE 3
#define STRING 100

[Code] .....