There are some complications you keep in mind when you try to date 14 C. as we told before, making samples is already one big complication. If you haven't got enough material, you can't date 14 C1.

The second complication is chiefly applicable on organic materials. Because of the differences of mass between 13 C and 14 C, the one will be absorbed better than the other. This is why there is less 14 C present in some kind of plants, which makes these plants seem older than they are. These differences in concentration are very important to keep in mind while dating wooden objects like the Round Table in Winchester. This complication can be dealt with if you test a sample for the 13 C-concentration. If you compare that with the 14 C-concentration it's possible to determine the true age of the object.

Another complication is the amount of 14 C in the atmosphere. It appears not to be constant. This inaccuracy can be corrected with correction graphs. In those graphs the differences in the concentration of 14 C in the atmosphere is placed in time. With these graphs you can determine how much the calculated age deviates from the true age, so it can be corrected.

The last important complication with the legend of king Arthur is the fish-effect. In the oceans, not only CO2 is adsorbed, but 14 CO2 too. In the oceans the older and deeper water mixes up with the ‘younger' water on the surface. Because of that the water seems older than it really is. This so called reservoir effect has more consequences that just making the water seem older.

Fish transfer this ‘old' water. People who eat a lot of fish seem older at the datings than they really are. Because of this a deviation of 400 years is possible, something that can be crucial when dating body linked to King Arthur. Fortunately this complication can often be solved. At archeological sites there are some other materials too, which can be dated with other methods.