Here is my version, which is as much alteration as paraphrase:
- Puzzle: The story hopes the heroes find this puzzle and spend time or resources to solve or disarm it. Which colored tiles are safe to walk on to cross the room? How should the levers be moved to open the exit rather than the monster's cage?
- Certain Death: The story hopes the heroes notice this trap's placement and also that they cannot nullify it. The trap must be avoided and exists only to redirect them. It does so with a satisfyingly suspenseful escape that focuses entirely on the current location.
- Forward Railroad: The story hopes the heroes do not notice this trap until it forcibly moves the heroes to a new place in the story. The heroes fall down a chute to a deeper level of the dungeon, are gassed unconscious in the wizard's tower and awake in a cell as toads, etc.
- Roadblock: The story hopes the heroes do not notice this trap until they trigger it, temporarily stopping the story. (Sometimes it is triggered yet the effect is not noticed until the heroes return to the location and then discover that an exit is blocked or an item is missing.) Yet it neither provides hints about what to do nor does it move the heroes along in the story. Instead the heroes must use the information they have gathered so far to decide how to respond to the halted progress.