Do the gas laws (Charles, Gay-Lussac ,and Boyle) contradict each other ?

Well, not exactly. It's very important to understand the assumptions that each law makes: Boyle's Law only holds true at constant temperature, Gay-Lussac's only works at constant volume, and Charles' only works at constant pressure. Since each law's assumption is violated by the effects of the others, you can't have a situation where all three are working happily side by side - for this, there is a synthesis called the Ideal Gas Law which states that for an ideal gas, PV = nRT, where P, V, and T are pressure, volume, and temperature, n is the moles of gas, and R is the ideal gas constant.

You're right that these laws seem to conflict, but the thing to note is that they all make assumptions, so in real situations you need to determine which one is more important than the others.

For example: if you take a piston and compress a gas, according to Boyle's law, the decreasing volume increases the pressure. This, under Gay-Lussac causes the gas to heat up, which by Charles' law would create a force to expand the gas - the gas, however, can't expand because the force from the piston is greater than the force from the increase in temperature.

Boyle's law states that while pressure increases volume decreases if temperature is held constant. You seem to be forgetting that the temperature is held constant in the case of Boyle's law, Now Gay-Lussac's law says that as pressure increases temperature increases as well if the volume is held constant so your statement that "the volume is decreasing" is incorrect because Gay-Lussac's law clearly states that the volume MUST be held constant.

P.S. Boyle, Charles and Gay-Lussac's laws are not really "laws" by current standards. They don't hold true if the pressure and density of the gas is too high.

All of these laws look at gases that change when certain characteristics change, and while others remain constant. Boyle's Law - Looks at pressure change with volume. Temperature remains constant Charles's Law - Looks at volume change with temperature. Pressure remains constant. Gay-Lussac's Law - Looks at pressure change with temperature. Volume remains constant. The findings: Boyle's Law - Volume increases, pressure decreases. (P1V1 = P2V2) Charles's Law - Volume increases, temperature increases. (V1/T1 = V2/T2) Gay-Lussac's Law - Pressure increases, temperature increases. (P1/T1 = P2/T2) (1 = situation 1, 2 = situation 2) Together, these three laws can be combined (such that all three characteristics can change and none are held constant). This is known as the Combined Gas Law, and essentially is: P1V1/T1 = P2V2/T2

The gas laws are consistent and confirm each other's findings. Simply consider the equation

(PV/T) = constant

and you will always be on track.

Hope this helps.