Once you’ve chosen the stone that you’ll be cutting (by clicking on it’s icon with the left mouse button), you’ll be presented with the flint cutting screen. Your flint will appear in the middle of the screen and your mouse cursor will change into the cutting stone, with which you will make the flint.

You manipulate the cutting stone by moving your mouse. The cutting stone will move on a 2 dimensional axis, as the cutting indicator will indicate (a semi transparent aura around the flint). This indicator will be useful to see if your cutting stone is properly aligned with the fragment you wish to hit. A good rule to follow is, if a fragment is completely coloured by the aura, it’s situated under your rock, inversely if it’s not in the aura, it’s above. The fragments that are properly aligned are those that have a part in the aura, and a part outside of it.

If the fragment that you wish to destroy if not properly aligned, you will have to pivot the stone. In order to do this, use the keys A-D, 4-6 of the keypad, or the left and right arrows. You will often have to pivot the stone 180 degrees in order to hit the fragments that are on the opposite side. To rotate the flint 180 degree use the S key, or 2 on the keypad, or the down arrow.

To help you determine if your cutting stone is properly aligned with a fragment, you can move the mouse while keeping the right mouse button pressed, which will rotate the camera around the flint. You can also regulate the brightness of the aura with the scroll wheel on your mouse. If your mouse doesn’t have a scroll wheel, use the – and = keys.

The flint is divided into fragments which each possess a certain resistance indicated by its colour: dark fragments are weak while light fragments are more resistant. More resistant fragments require a stronger hit to destroy. The faster you move your mouse, the harder you will hit the fragment.

The force of impact of your last hit is shown in the information bar situated on top of the screen. The last fragment you’ve hit is coloured with an orange tint. With the information bar you can judge the strength of each of your hits on the fragments.

Each flint is composed of 2 types of fragments: those of which you must destroy are coloured grey, while those you must preserve are yellow. Each time you destroy a yellow fragment the quality of your flint will decrease, as shown on the left side of the information bar. Should the quality of the flint ever reach mediocre, it has been damaged beyond repair and you must start a new one.

Each hit on the flint is counted. The more hits you need, the more your efficiency will decrease. Once again should your efficiency reach mediocre, your flint is useless and you should start a new one. To maximize your efficiency you can give harder hits, which will allow you to hit multiple fragments at once. But be careful, with harder hits you risk to hit a yellow fragment that will decrease your flint quality.

Should you wish to stop cutting a flint in order to start another or just to return to the valley, just hit the ESC key. The current flint you are working on will be lost.

Should you succeed in destroying all of the grey fragments on the flint, you will gain a new flint (spearhead), but only on the condition that both the quality and efficiency are better than mediocre. Also the higher the quality and efficiency, the more tribal points you will be awarded.