What They Are and What They Do
Pathfinder 2e uses a “metacurrency” (a currency which has no in-character representation) called “Hero Points”. Players begin each game session with one hero point, and the GM awards more during play. You can have as many hero points as you like, but they go away at the end of the session, so it’s a “use it or lose it” situation. Don’t hoard them.
Players can spend a hero point to reroll one check, using the second result instead of the original roll. This is a “fortune” effect (see our article on PF2’s tagging system), and only one fortune effect can apply to each check. This means that you can’t use another hero point, another ability which gives you a good reroll, or other stuff like the Guidance spell.
You can also use all of your remaining hero points, no matter how many you might have, to stabilize while dying. This occurs when your “dying” condition would increase, removes the dying condition and makes you “stable” so you won’t die unless you take more damage. More on death later in these articles.
Awarding Hero Points
The GM is expected to award one hero point roughly every hour of real-world play time. So if you play a 4-hour game session, the GM should look to award 3 or 4 hero points throughout the session. The rules encourage awarding them for heroic action and for clever planning, and those are both great ideas.
For more on handling hero points, especially on how to not forget about them, check out out podcast episode about metacurrencies.