Lastly, you may take a hit, which you’ll need to absorb with stress or consequences, or suffer some other drawback. This sort of failure is most common when defending against attacks or overcoming dangerous obstacles. This is different from a simple failure because the character alone, not necessarily the whole group, is affected. It’s also different from success at a major cost, in that success isn’t necessarily on the table.

Ethan is able to get the safe door open, but as he grasps the handle, he feels a jab in the back of his hand. He couldn’t disable the trap! He writes down the mild consequence Poisoned.

You can mix these options together: Harmful failure can be harsh but appropriate in the moment. Success at the cost of harm is certainly an option.