Unlimited action points:
Choose any mission and four characters. Equip, then deploy the characters. Click on the blueprint icon on the main menu. Refer to the faces of the four men as numbered from 1 to 4 from top to bottom. Select each character in the following order, then click on the top left arrow to return to the game: 3, 4, 1, 2, 2, 4, 1, 3.