removed static

src/GameClass.java

 public class GameClass {
 
     public static void main(String[] args){
-        while (RockPaperScissors.playerScore < 7 && RockPaperScissors.computerScore < 7) RockPaperScissors.runGame();
+        RockPaperScissors match = new RockPaperScissors();
+        while (match.playerScore < 7 && match.computerScore < 7) match.runGame();
     }
+
 }

src/RockPaperScissors.java

-import java.util.Scanner;
-import java.util.Random;
+import java.util.*;
 
 public class RockPaperScissors {
-    static int computerScore = 0;
-    static int playerScore = 0;
+    int computerScore = 0;
+    int playerScore = 0;
 
-    public static void runGame() {
+    public void runGame() {
         int computerInput = letComputerChoose();
         int userInput = letUserInput();
         convertToWordUser(userInput);
         checkResults(computerInput, userInput);
     }
 
-    public static void checkResults(int computerInput, int userInput) {
+    public void checkResults(int computerInput, int userInput) {
 
 
         if (computerInput == userInput) {
         return userInputWord;
     }
 
-    public static String convertToWordComputer(int computerInput) {
+    public String convertToWordComputer(int computerInput) {
         String computerInputWord = "";
 
         if (computerInput == 1) {
         return computerInputWord;
     }
 
-    public static int letUserInput() {
+    public int letUserInput() {
         int userInput;
         Scanner input = new Scanner (System.in);
         System.out.println("1 for Rock, 2 for Paper, 3 for Scissors: ");
         return userInput;
     }
 
-    public static int letComputerChoose() {
+    public int letComputerChoose() {
         Random rgen = new Random();
         int computerInput = rgen.nextInt(1,4);
         return computerInput;