The world war 1 introduced a number of fighting techniques, including the use of poison tanks. Many nations needed the tanks but a few of them had the resources to acquire them. France and Britain were the intellectual tank designers during and after the world war 1. Proper use of tanks was guided by ideas such as weight, size and mobility. Armies preferred small and turretless tankettes. As many countries produced armoured vevicles, armies increasingly used light tanks.