I'm thinking about some enhanced rules for Synapse effect when GM'ing those wacky Nids. Primarily it's give to give some nicer obvious RP effects, secondarily it's a chance to include some glaring (only to me no doubt) ommisions.

Synapse rating. At the start of combat write down the synapse rating of the Tyranid opposition. This is measure of number and power of Synapse creatures in the area. Select the most powerful creature with the Synapse trait, add it's WP and INT bonuses together. Then add the INT of every other Synapse creature in the vicinity.

EG. If a force of Tyranids includes only 'gaunt' sepcies and a group of three Tyranid warriors the Synapse rating would be 11 (5WP+2INT+(2x2INT)).

Exerting synapse. Synapse points are spent to increase the focus of the connection and teamwork of groups of Tyanid creatures. For each group (and distinct team of like creatures), horde and single creature may have Synapse points spent at the start of combat to give them any of the effects listed below. However, each group, horde or creature must have 'Synaptic Link' spent for them before any other points are spent on them. Effectively the points refresh every turn and all spends are for the duration of that turn but normally the points are spent each turn in the same way as the last turn unless something happens to effect the amount of points. The GM could also decide that significant changes in battle conditions could have the Synapse (effectively the most powerful Synapse creature) make a WP roll to change the points distribution.

Synapse Effects:

Synaptic Link, cost 1. The creatures are fully linked to others Tyranid creatures in the Area. Effects, the Tyranid creatures gain the talent Double Team, If any Tyranid creature with Synaptic Link that is can see a character then all Nids with Synaptic Link are aware of them, although direct attack may still suffer the -30 penalty to hit a target they can't see although some blast weapons might make direct targeting unnescesary. Perception tests made by a Nid with Synaptic link are assisted (i.e. +10) by any other Synaptic linked creatures with potential los to the target.

Creatures within synapse range that do not have Synaptic Link established only overcome their instinctual behaviour.

e.g. In the above example the Three warrior group could establish a Synaptic link with 10 other creatures, groups or Hordes.

Tyranid Tide , cost 1. Groups of creatures move and flow around attacks like water. Hordes with this ability have the ability to dodge attacks.

Synapse resistance, cost 1. Tyranid creatures with this ability gain a bonus to resist mind controlling or fear effects of +10 for every creature with the Synapsetrait linked to them (creatures with unnatural WP donate a bonus of 10 x thei Unnatural WP trait).

That's all I've got time to do at the moment, I'll think of some more later. I know this is going to be too complicated for most GM's, in fact it looks a longer written down than I was expecting but I think the core mechanics are pretty simple.

I like the idea of giving enemies squad mode equivalents, however as to your examples, nids are already immune to Fear and Tyranid Tide may be game-imbalancing.

Kshatriya said:

Well the fear mention I added because I wasn't sure I'd seen all the rules and whether or not anything overruled the natural Fearlessness, Psychicly caused fear for instance. But I really liked the idea of having to fight the hive mind for control of the beasts if it's used often enough for the hive mind to watch it (i.e. spending the points ahead of time).

Balance wise it is of course down to the GM, I don't know whether it was worth including the points at all really other than as a guide. Re dodging though, it would certainly slow the game down if everything dodged (the real worry I think), but I think it's useful, for example showing that the Hive Mind is learning, or getting desperate, as I was typing I couldn't decide whether to put it as 1 or 2 points, perhaps it's worth putting it even higher.

Still not thought about any other options, at the moment I'm just trying to think of any moves that hordes aren't normally allowed that might seem to fit the bill.

Looks like I've got a game to GM in the near future. I plan on using these rules at points when the players have specifically drawn the attention of the Hivemind.

Skulking Shadows, cost 2
'They're using the trees!'
The synapse mind drive's it's creatures into the recesses skulking just out out of view dashing everytime their enemy turn their backs. Creatures with this effect gain +10 to Silent move and concealment tests. In addition, as long as one linked creature can see the targets, all creatures with this Synapse effect gain an additional +10 to these rolls and may also move as twice the normal speed while moving silently.

Aim Coginition, cost 2
The synapse uses the linked minds like a super computer, gathering data on failed shooting attacks and feeding the experience to the creatures. Creatures with this effect gain a +10 to Bs tests.

Intellegence boost, cost 1
'How could they turn off the power, they're animals?'
The synapse guides the creatures with it's hive mind intelegence, creatures that were acting like little more than animals before now start using tactics, terain and start to attack weak points. All Creatures with this effect gain +10 int, as well as certain battle field knowledge such as the ability to recognise essential power converters, vox relays, unhidden traps and important personnel

Bodies Before Bullets

Cost: 1

"They told us to shoot at the big ones, like they told us to. But it didn't help, the little ones just kept jumping in the way!"

The Synapse creature can force smaller Tyranids to leap into the path of incoming rounds. This synapse power can be used in place of a reaction. THe creature makes a Challenging (+0) Willpower check - if successful, the attack is resolved against a Horde within Willpower Bonus yards of the line of fire.