Subtle but simple changes... True Day/Night transitions. Add fog as a weather condition. Some variation in the Zeds (walk only and maybe a upper torso crawler types) Zed packs (3 or 4 that stay in their group) Small % of Zeds actually found in houses. An addition to the map consisting of a large city (multiple high rise, basement garage, subway station) Real Zed infested area but high loot risk/reward area. Some areas/houses that can be completely closed/locked. Players can open but Zeds can't. Not as easy mode as it sounds, its alright locking yourself in but eventually you still have to go hunt for supplies ! Traps - You got a shovel... you can dig a pit (got an axe... you can add spikes) Good against Zeds and enemy players. Bear traps... Players can open them but still take damage. Zeds are dumb and just stay trapped. (Claymore - Rare find at military base. One use only AND remember where you put it...lol) Buckets, pots etc can be left outside to collect rain as fresh drinking water. (Not in great amounts and possibility of somebody else stealing it) Lastly... a sleep function. (Find a bed, sofa or sleeping bag and you can 'sleep' Gives a 10% increase in recovery speed and a 20% reduction in water/food consumption while you are in 'sleep' mode. Hmm...