Planning and Improvisation
With any open ended “sandbox” style game (I.E one where the players are pretty much free to go where they please and do what they wish,) it can often be easiest to only plan a short distance ahead and try to react to player choices; rather then overly anticipate their decisions or guide them in any specific direction. When letting players drive the plot, it lets you more easily plan future adventures based on the PC’s current plans and immediate goals, making the preparation for the next session relatively fast and simple.
For example, your session ends with a group preparing to travel in their newly acquired vehicle to an airfield and acquire a plane of some sort. Knowing the groups current plans and immediate destination, You can easily prepare the upcoming encounter locations to make the journey to the airport, and the airfield itself flow smoothly.
Granted, not every session ends in the perfect place for you to anticipate the groups’ next move or direction, but Iyou can usually either ask the group out of character what their plans are, or arrange for a friendly NPC to ask the characters where they’re traveling next. (Perhaps providing them with some useful info on what lies in that general direction.)
Zombies aren’t the only Enemy
While the zombies are the main threat and theme to the setting, They often work best when applied sparingly, and where they will have the largest dramatic impact. If nearly every combat encounter in their travels is nothing but zombies, players quickly grow familiar and jaded with the undead threat, which greatly diminishes the horror and suspense of the setting.
As in any other post apocalyptic game, the main threat is not so much the aftermath of the apocalypse itself, (be it zombie, radiation or biological,) But from fellow humans, and the resulting chaos from society attempting to cling to, (or abandon entirely) the remnants of civilization. This human element, as well as the threat from others dangers both living, (such as escaped zoo animals and feral pets,) and environmental, (such as storms, fires, destroyed bridges, temperature extremes) provide a broad variety of challenging encounters, and ones that pure combat ability and weapons won’t always help overcome.
When the zombies do make an appearance in your campaign, try to make sure it is in a situation that is either dramatic itself, (such as the horde of zombies during a severe thunderstorm,) or otherwise presents opportunities for an exciting or suspenseful encounter. (Such as the child zombies in a confined area.)
Much of Survival Horror is Survival
I your campaign try to empathize the survival aspect, the challenges of simply trying to stay alive in a world where nothing is easily acquired and potential danger lurks around every corner. Zombies, road gangs, and other such combative threats are far less exciting and suspenseful when your players have a healthy stockpile of ammunition and enough supplies to travel the wastes for weeks without needing to scavenge.
In order to keep things gritty and difficult make sure to have the characters sweat and/or bleed for every reward and upgrade they acquire, rewarding good ideas and smart tactics, while still ensuring their plans never go too smooth. A few unforeseen complications or unexpected combat encounter can turn an otherwise “typical” scavenging or planning scene into a memorable encounter, (such as the inclusion of a wild animal nesting near stockpiled supplies.)
Usually most groups will expend enough ammunition and supplies to continually have to hunt for more, but at times throwing in an extra combat encounter to help drain their resources and keep them needing more. (Such as the horde of zombies.) When your players come up with a masterful plan or perform some stellar roleplaying, make sure the reward is worth the effort, and that the challenge of future encounters will take the benefits of this reward into account.
Pacing Action and Interaction
The other technique you can use to keep sessions fresh and exciting is mixing up the combat encounters, usually with interaction or exploration scenes which create opportunities for character development and interaction within the group. After a particularly tense and combat heavy session or two, It can be good to slow down the pacing for all or part of a session. This lets everyone reassess the current situation without feeling overly pressured and driven to charge full speed ahead. Giving some regular in game “downtime” allows not only your players to strategize, but gives you a clear idea on what to plan for next, without needing to rely upon improvisation or leading the players with an obvious plot hook.
Drop in Encounters
The last method to help keep things flowing smoothly is to keep a few short encounters ready at a moments notice to toss in when things slow down, or the group is eager for combat. These encounters are usually rather simple, from a random rabid animal lumbering towards the group from the bushes along side the road, or a zombie bursting from inside a port-a-potty, it gives the session a hit of adrenaline that revitalizes everyone and keeps things from dragging.
Does anyone else have a few techniques they’d like to add for keeping zombie games fun and horrifying?