I was thinking of a couple of rules to make nids more authentic and one area that Nids don’t act like their fluff is the way that Nids will sacrifice their lesser creatures for the hive.
A common Tyranid tactic is to overwhelm by numbers, caring nothing for the sacrifices made to achieve their goals. Gargoyles throwing themselves into Jet engines to bring down fighter planes, Hormagaunts throwing themselves into gun lines to protect the creatures behind them, or to simply clog the battlefield.
Creatures with the “Sacrificial Swarm” Rule gain the following abilities while in Synapse Range -
Sacrificial Cover - When a shot passes through a unit with Sacrificial Cover, to strike creatures / units behind it, as judged by LoS from the firer, the Unit may elect to give the unit behind a 3+ cover save. If it does so, it immediately takes 1d6 wounds, with no saves (cover or otherwise) possible.
Sacrificial Weapons - A unit with the Sacrificial Weapons rule that assaults a Vehicle may elect to sacrifice themselves in an attempt to take down the vehicle. To use this rule the number of models within the unit must be equal to or greater than the greatest armour Value of the Vehicle being assaulted, which in most cases is the front armour. This attack has no affect against Super Heavy Vehicles & Titans
Before the Attacks from either side have been rolled, the Tyranid player must select a number from 0 to 5. This number is the “Sacrifice Ratio”. The Sacrifice Ratio is added to the strength of each of the creatures in the unit, (not attached independent characters) for their attacks against the Vehicle this assault phase. Roll to Hit and Penetrate as normal (which in close combat is against the rear armour). After combat has been resolved, including casualties for any vehicle explodes result, roll a number of D6 = the Sacrifice Ratio chosen, the Tyranid Unit takes this many wounds with no saves (Armour, Cover or Invulnerable) possible. Note that the Strength bonus gained in this way does not stack with Furious Charge. A Unit may Elect to do this if they are rammed, however an additional D6 is rolled when the Sacrifice Ratio dice are rolled.
I was thinking that the Following Units would gain the special Rule “Sacrificial Swarm”:
(I’ve not included Stealers as I believe that their independence from the Hive Mind works against this rule. This is meant for dumb sacrificial troops)
I think that the rule is self-destructive and the use of it will remove your own nids faster than normal. Thus I don’t think that there should be a cost associated with it.