 <p>You forgot the curly braces for the else-statement of your "recursive case" ...</p> <p>This does work:</p> <pre><code>private static void combos(String counter) { if (counter.length() == userinput) //base case System.out.println(counter); else { combos(counter + "A"); combos(counter + "B"); combos(counter + "C"); } } </code></pre>