Action points, or AP, are what we use to make sure everyone gets their fair share of involvement in things happening around the grid.
You can have a maximum of 300 ap at any given time and your weekly ap gain will be listed on you inventory as well.
Action points can be spent to do various things in game. The most prevalent one is submitting story @actions. A story action is something you can do alone or with others. This is where you tell staff 'I have a goal and here is how I wish to accomplish it'. Something this may result in a GM'd scene, or sometimes it can be handled off screen with a small story write up. This will be your most prevalent way to increase or decrease reputation as well.
There is a large write up on how @action works. To see it type 'help action'. At the bottom of the help file you will see 'You are permitted 2 actions and 2 assists every 30 days' followed by a tracker of how many actions and assists you have taken in the last 30 days.
AP is also used when crafting items at a vendor shop. You can pay more action points to decrease the difficulty and increase your chance at higher quality items.