Only Ultimate and Tournament modes are planned to have support for authenticated online scores.
Arcade: No friendly-fire. You do not set off your own traps. Among other things which make the game easier.
Ultimate: Rules are more realistic. Friendly-fire on. Traps damage all players (even the owner). Makes game harder.
Campaign: You must rescue survivors. Some civilians can fight while others may have special skills (e.g. defusing land mines or other traps). Has a story line.
Tournament: Player's only have a certain amount of air supply for their gas masks. At specified intervals, air supplies are air dropped. Enough for all but 1 person. If a player's air tank runs out, they have about a minute before their character takes off the mask in order to breath. In which case, their character is infected with the Medeiga Compound (which turns them into a zombie). Players get bonus points for killing each other. Ultimate Mode rules apply. When there's 1 player left (or none), the person with the lowest score is eliminated. If more than 1 person has the same lowest score no one's eliminated. Then everyone is respawned. Keeps going until everyone's eliminated. Final score will be based on player kills * ( zombies killed * 60 - seconds game lasted ).
Mole: Only silenced guns, melee weapons and traps deal damage to other players. At night time, all weapons are allowed to deal damage to players. Final score will be based on ( player kills * 300 - seconds game lasted ).
Civil: Human rights activists argue that it's more "civilized" to lay traps rather than directly attacking zombies, who used to be people. Only emplacements (e.g. sand bags, land mines) are air dropped. Arcade Mode rules apply.
Laser Tag: All players start off with the L10 laser rifle. Batteries are air dropped around the map. At the beginning, host chooses what score to play to. Each player killed gives 1 point to the attacker. Players respawn after getting killed. Whoever reaches the end score first wins.