I have some ideas for the zombie system and the zombie bots. This could be more challenging and difficult to avoid it unless you know how to avoid it. Don't lock it. I could add some more ideas for this topic. These ideas maybe for fun but its a challenging thing to do or etc.
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Zombie system:
+Zed's stamina:
If in logic,zombies have infinite stamina correct? If so let it be infinite but add a bar system shows the time limit on stamina.
(Set the time limit about 2-5 hours or just add the time to revive again as survivor)

+Infecting:
Add an infecting button to allow us to infect survivors whom we are fighting or etc. That may let our opponent to face death even we died of their attacks.The infecting could let our experience to gain when our infected victims dies by the affect of infection. Add also a button of choice of choosing whether to bite or claw(attack normally). It could help the game be more role-play.
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Survivor system:
(Solution for zombie system no.2)
If we ever get infected,we could search or buy some anti-virus in the hospital,safe zone(camps),in any pharmacy/supply depot/ or any emergency vehicles and even more.

+Inventory:
We should have effect on inventory whenever we found or buy a backpack,suitcase or anything that we can keep it in.
(You could ignore this if it is not so a good idea)

+Sleeping system:
Following on logic,sleeping could regenerate stamina or avoid us on stress or anything. Add a bar of stress,sleepiness or any of the effect. We could use some sleeping bag or a cardboard box to use as a camouflage while we're sleeping at a park,apartment,barricaded shops or etc.

+Starvation:
Food and water are important things to have in our lives. I suggest to add a simple bar of starvation on the "Character" page and the toolbar above the game.
(I know there are a lot of topic about starvation system but just want to add it in here. It could help the game be more role-play)

+Transportation:
We can use vehicles that are not so damaged,have fuel,movable and etc. This could help us on avoiding our stamina to decreased faster. The fuels can be found on scavenging at a fuel station or workshops nearby. Before scavenging on fuels,we should have empty fuel tanks first before taking fuels from the gas tanks at the fuel station. This could increase more role-play on this game.
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