Firstly all these ideas would have a big effect on the game and may not be possible to implement them. They are all ideas off a mod i have played called Experiment for Garrys Mod. Currency What can i say? A coin or item which could drop from zombies etc.. Could be used for playing trading or npc trading? This would add a reason to actually kill zombies. Perks Perks you could buy off npcs or off the ingame menu/interface. For example a perk called Bear Grylls which would reduce the amount of hunger and thrist you lose by 50%, so ultimatly it would take longer to fully dehydrate. Another idea could be Berserker which would increase all meele weapon damage by 25%. There could be many variations, these would be bought with the currency you have gained and would be whiped on death. Npcs Standard npcs you could buy stuff from. Maybe rare npcs near crash sites etc which sell the rare ammo etc or hunters in the woods which would sell or trade meat etc. Stats/Attributes Attributes as follows Every attribute has 100 points which can be earned, on character creation you would have 30 spare which you could put into any attribute/s of your choice. For example you would gain Agilty by sprinting, gain endurence by taking damage etc etc. Strength Do more meele weapon damage, carry more items. Agility Run faster Stamina Run for longer Endurance Take less damage when hit /// Or increases total blood Medical Decreases time to bandage and other medical equipment Morality So you would start with neutral morality. This would be an indicator for bandits/survivors. For example if you would -morality you would be classes as a bandit and when people hover over your name it would say bandit or be red. If your + morality you would be a survivor that people could trust. You would lose and gain morality based on things you do. So if you kill a bandit with -morality you would gain morality or if you bandage and blood transfusion somebody you would also gain a amount vise-versa. Now alot of these ideas could have alot more to them and these suggestions are a breif overview.