Tyranid Infestation - initial fluff, more is under the Siren entry in Non-combatants comp here (viewtopic.php?f=40&t=14716
A Tyranid strategy that is becoming more common is secondary infestation. This is being used where resources cannot be directed in a full frontal assault, due to a scarcity of biomass or where the fleet need to draw enemy resources away from a key strategic asset. It only works well in cases where the planet has either a large civilian population or large amount of living biomass in the form of plants and animals. If there is too sparse a biosphere or too high a proportion of armed personnel then this mode of attack invariably fails. It can however be used to draw significant resources away from a defensive position, or to sow discord and chaos before a genuine assault.
The organisms that the Tyranids have bred to perform this type of attack are bio-engineered with one aim in mind – proliferation. The creatures are able to reproduce and spread without any stimulus from the hive mind. They are designed to operate independently of the Tryanid race’s usual reproductive method i.e. in the gestation pouches derived from the Norn Queens. They hunt creatures or eat vegetation in order to produce more of their kind. They are all partly or fully omnivorous, and can reproduce very rapidly on any biomass that they can get their teeth into. Most of these creatures are not the common Tyranid assault creatures however some are used in both roles, for example Genestealers have been regularly used in this role because of their ability to infect a population and reproduce efficiently. Lictors and Hormgaunts have also been known to be deployed ahead of a main fleet, though without the Hive mind, Hormogaunts are less effective than in assault swarms.
The result of this is that the planet under attack quickly finds that its wildlife has become much more voracious and that new strains of creatures are rapidly becoming predominant to plague like proportions. These new creatures are also not fussy about their diet and are quite prepared to prey on the sentient inhabitants. Therefore the native population quickly find their movement impeded and their lives at risk form the new fauna and flora as their world rapidly transforms itself into a Death World.
Infestation games are small games where a team of troops attempts to navigate, cleanse or just survive in an infested area. Idea is for a very tense but fun small games where 5 - 10 man (and woman) team to try and fight their way through the creeps. all your survivors should have names to get the desperate personal feel of the thing, and focus upon manipulation, psychology and individual peril and heroism...
Right, thought so far, i have fiddled with main 40k game rules - but not tested them yet - i prefer to test with nice models, so am sculpting them...
Missions that can be played;
1. Cleanse – multiple squads are deployed to cleanse an area of infection.
2. Rescue – Survivors are dispatched to save important personnel or civilians who have become trapped. These join the rescuing troops upon their release.
3. Escape – a group of Survivors finds themselves caught deep in heavily infested territory and has to fight their way clear.
4. Salvage – A group of Survivors need to collect or reactivate vital components abandoned in a heavily infested area.
5. Sample – A group of Survivors are required to get a biological sample of some important invasive creature and make off with it.
6. Survive – The infestation has reached the point where it is capable of summoning or spawning a Tyranid assault. The survivors simply have to keep one member alive until the end of the game, as the creatures close in on their position, so that they can warn the recovery mission of the planets plight.
The whole game is played as a skirmish game, and all non-Tyranid models are treated as independent characters for the duration of the game. Even when they have grouped together in squads they can still pick separate targets and even assault independently if they wish. Once in normal squad coherency they also gain the usual benefits in terms of wound allocation. Bonuses that affect friendly squads only affect more than one model if they are in unit coherency and they are behaving like a unit under normal 40K rules. If one model leaves the unit or opts to do something that would normally require the whole unit to take part e.g. go to ground, either he or the remainder of his unit immediately forfeit the special bonus and are no longer counted as a unit – players choice. Additionally if a model suffers an attack that causes the model to do something unusual (outside the scope of normal squad rules – e.g. compulsory movement or firing on his comrades) then that model is also removed from the squad though the owning player still chooses who retains any beneficial buffs.
Moral is rather more complicated, and is worked out on a model-by-model basis, and at the end of the players turn. Moral checks are now taken by any model that witnesses 25% of his comrades who are in line of sight killed in any one player turn. (e.g. a team of five men enter a room leaving one to cover them. Two men are killed by a strangler pod. Both the other two men in the room could see this and must take moral tests, the man outside could not and is immune.
The last rule change is covering fire. A non-Tyranid model may forfeit its entire go in order to provide covering fire in a specific 90o arc of fire. A model that opts to do this is given a special marker showing what direction he is covering and may then shoot at any point during the Tyranid player’s movement phase, even interrupting the movement of a model/unit to take his shot at any unit in or moving through that 90o arc of fire and within the shooting models LOS. (roll on old overwatch)
Other than these alterations, all normal 40k rules apply. Infestation markers
These are revealed either by the survivor player spotting them (see below) or when a Survivor model moves within six inches of a marker. The Tyranid player must then immediately reveal what the marker is and deploy the creature (s) anywhere within a three inch radius of the marker.
Spotting a marker. Any marker that is within 24” of a Survivivor model may be spotted. Spotting takes the models whole movement phase as he or she studies the area to try to determine what the threat is. To attempt to spot a marker simply announce that a specific model is attempting to do so after all movement has taken place and then roll a D6. On the roll of a 6 the Tyranid player must reveal the creatures the marker represents. Several attempts may be made on one marker per go by several different models. Models that have attempted to spot a marker (regardless of outcome) cannot move or assault that turn but may shoot (or run) as normal.
The tyranid player may choose to voulentarily reveal any markers he chooses at the end of his go, that are within 24 inches of one or more survivers. these modles may not make any actions untill the tyranid players next turn.
Things i want to include - lots of ambush creeps, brain lech zombies, the G Cult, cool events for both the suvivors/guard and the nids, few codex units... and (gasp) little synapse!
Tyranid worms (and their burrows)
fleshborer hives (and other hives)
Digestion bugs + rippersTyranid WebweaverSporvigon curtesy of sofacoin
some codex stuff - lictors, stealers H-gaunts (and possibly venomthropes - i love the model but little else).
the dreaded Ambassadors (not quite like the fantastic Hydra sculpt)
and many others
Concept sketches coming soon.
There is more like species details but will add that when i have more time... please post any ideas suggestions;