Each Command card has Points and Keywords that help you know how to use the cards in the game, these are explained in the Command Card rule insert.
Command cards can be added to your force in two ways. You can add them to your normal point limit just like you would add a Unit to your force, or you and your opponent can agree on a set amount of points that players may only use to add Command cards to their lists.
Command Cards allowed us to take some of the more complex rules that are not easily covered in an army book and put them onto cards so that they are easily referenced during games. Players can choose how to use Command Cards in their games. For example each player can have a set amount of points dedicated to Command Cards, or players can add Command Cards directly to their lists spending points as normal.
Most Command cards are hidden until they are used, so you're never quite sure what your opponent's battle plans are until they are revealed. While hidden Command cards do not affect their attached unit, a player must reveal them if they wish to gain the cards benefits. Some Command cards must be revealed at the start of the game, these cards are used to build your army and have the keyword Build.