When you start gaining XP in Assassin's Creed, ability points will follow. You can spend these points in your skill trees, which focus on the Warrior branch (melee combat), the Hunter branch (ranged combat), and the Seer branch (which is sort of a catch-all containing everything from sleep darts to animal taming to chariot ownership to getting better prices from merchants).
You may be tempted to do some dabbling in the different trees to build a well-rounded character, but trust me on this: make a beeline for the Enhanced Predator Bow ability in the Hunter tree. It's extremely fun and highly useful, since it turns your arrows into guided missiles.
Above, witness me taking out the commander of a ship, completing an objective without getting anywhere near the ship itself. Steering the arrows while they sail through the air gives my shaky aim some much needed accuracy, and the slow-motion gives the commander less time to freak out and take cover after the first arrow splashes his lid.
It's just great to be able to aim after you fire. Below, I was attacked by a lion three levels higher than me, which then fled after I set it on fire with a bomb. I could see its outline through the trees but it was running fast, so I just sent a couple predator arrows in its general direction, making course corrections to plunk a couple of shafts into its butt. I then finished it off with a few headshots when it turned to come back at me.
It's also useful for striking targets behind cover, by manually giving your arrows an arc. While infiltrating an enemy camp, I drew the attention of some guards and had to hastily scramble behind a tent. On the other side of a wall was a caged lion, but the wall was in the way of my shot. No worries, though, I just popped a predator arrow into the air and steered it over the wall, freeing the lion to cause some havoc.
You can unlock the Enhanced Predator Bow skill along two different paths, but the less costly is to head straight for it along the Hunter tree, using a total of four ability points. (You can also reach it from the Warrior tree, but the extra step will require an extra point.) Once you've got it, you aim your bow by holding the right mouse button, and fire and control the arrow by holding the left mouse button. This takes a wee bit of getting used to, since your other bows fire by releasing the left mouse button, and this is done in the reverse.
You will, naturally, need an actual predator bow to use the skill, but I found one easily (and quite cheaply) at the blacksmith shop in Siwa, the starter city, and I've seen them for sale in other shops on the map. And yes, I did attempt to fire an arrow and turn it 180 degrees to shoot myself in the face, but the arrow simply doesn't stay in the air long enough.
For more Assasin's Creed: Origins, check out our review in progress.