botSnippet01.js

hears(['play'], 'direct_message,direct_mention,mention', (bot, message) => {
  const { user, channel, text } = message; // destructure message variable
  const userData = text.match(/<@([A-Z0–9]{9})>/); // parse the text for user's 9 character id

  if (userData) {
    // if there is a user challenged, start the game
  } else {
    bot.reply(message, 'You didn\'t challenge anyone…');
  }
});