The solution is different in each game, but here’s a couple of my thoughts:
- Have multiple solutions for each problem. Is there a giant ogre guarding the entrance? Maybe there’s also a hidden entrance. This way newbie players can still progress in the game, but more hardcore players might decide to take on the extra challenge of the ogre instead.
- Make harder challenges optional, but with rewards, so players will be more likely to at least give them a chance.