diff --git a/src/c/ticTacToe.c b/src/c/ticTacToe.c
index c2347cb..5eab4a2 100644
--- a/src/c/ticTacToe.c
+++ b/src/c/ticTacToe.c
@@ -1,14 +1,11 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdbool.h>
 
 #include "ticTacToe.h"
 
 
-int something(int a){
-    return a;
-}
-
 void printPrompt(){
     printf("Let's play Tic Tac Toe. You will use O, I will use X.\nJust enter the number of the field you choose as row col.\nYou start.\n");
 }
@@ -37,5 +34,15 @@ void getPlayerInput(char field[3][3]){
     int row, col;
     printf("Enter the field as row col: ");
     scanf("%d %d", &row, &col);
+    row -= 1;
+    col -= 1;
     field[row][col] = 'O';
+}
+
+bool validateUserInput(int row, int col){
+    if (row < 3 && row >= 0){
+        if (col < 3 && col >= 0){
+            return true;
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/c/ticTacToe.h b/src/c/ticTacToe.h
index 832972c..250a462 100644
--- a/src/c/ticTacToe.h
+++ b/src/c/ticTacToe.h
@@ -1,10 +1,11 @@
 #ifndef TICTACTOE_H
 #define TICTACTOE_H
+#include <stdbool.h>
 
-int something(int a);
 void printPrompt();
 void printField(char field[3][3]);
 void initField(char field[3][3]);
 void getPlayerInput(char field[3][3]);
+bool validateUserInput(int row, int col);
 
 #endif
\ No newline at end of file
diff --git a/test/c/test_ticTacToe.c b/test/c/test_ticTacToe.c
index c76d3f9..d912a7a 100644
--- a/test/c/test_ticTacToe.c
+++ b/test/c/test_ticTacToe.c
@@ -1,6 +1,7 @@
 #ifdef TEST
 #include "unity.h"
 #include "ticTacToe.h"
+#include <stdbool.h>
 
 void setUp(void)
 {
@@ -10,17 +11,17 @@ void tearDown(void)
 {
 }
 
-void test_runExampleTest(void)
+void test_ticTacToe_validUserInput(void)
 {
     /* arrange */
-    int result;
-    int input = 1;
+    bool result;
+    int row = 2, col = 0;
 
     /* act */
-    result = something(input);
+    result = validateUserInput(row, col);
 
     /* assert */
-    TEST_ASSERT_EQUAL_INT(1, result);
+    TEST_ASSERT_EQUAL_INT(true, result);
 }
 
 #endif // TEST
\ No newline at end of file