Maybe politics has broken down or the enemy is just single minded and you simply need to put them down before they put you down... it's time for combat. LARP combat rules are generally designed to keep all parties safe while still making sure that the characters fight with a suitable capacity.
Non-Physical LARP Combat
Some games employ non-physical combat rules (e.g. World of Darkness LARPs often use bouts of rock, paper scissors) so they can be played in urban venues that might have breakables close by.
Physical LARP Combat
Some games favour physical combat rules (e.g. use of especially made weapons to strike and armour to be struck) and most of them use a similar format too. Each character has a certain number of hit points allocated to a location, i.e. each leg, each arm, body and sometimes head. Each time a weapon strikes a location, a hit point is lost. When that location reaches zero, it cannot be used until the wound is treated (healing rules vary). Usually, if the body or head are reduced to zero, the victim must act unconscious and begin counting. They are considered to be bleeding to death and if their death count reaches a certain number, they are toast and must report their death to a referee.
There are also events that employ "global" hit points rather than "locational" (such as Empire LARP by Profound Decisions). This means you only have one location.... you. If you are struck anywhere, you lose hit points from your global hit points. For instance, if you have 3 hit points and are hit in the body, leg and arm, you are still rendered unconscious and dying.
There are lots of weird and wonderful variations on LARP Combat. Always read up on the rules to ensure you are fighting safely and fairly.
