With the recent release of the new edition of the Tyranid codex, there is a lot of to and fro about the quality of the army, how it stacks up against others, and what’s been addressed from the last edition. I’m of the camp that the codex is, overall, disappointing and weak. Disappointing as it did not address known issues, while nerfing things already considered subpar. Weak not just in the sense of tourney worthiness, but in also in being able to produce multiple lists built with different units that don’t leave one with the feeling that one is having fun despite the codex, not because of it.
I won’t echo much of the analysis I’ve seen elsewhere, but instead want to share a realization I had that underpins much of the issues people have. Which is Synapse and Instinctive Behavior are a net disadvantage, yet models are pointed as though it were neutral or even an advantage. In other words: if you were to strike every reference to the Synapse and Instinctive Behavior rules from the book, the result would be a stronger, more functional army list.
The reason for this is that Synapse and Instinctive Behavior are more of a disadvantage than an advantage. Models and units are actively worse off for having them, and the synergy of them across the army magnifies that. The only benefit that Synapse offers is Fearless: handy. But hardly unique or even unusual in 40K.
However, that Fearless is conditional on the proximity of specific models: Synapse Creatures, which are pointed based on having this bubble. Moreover, when a unit is not in Synapse, not only does it lose Fearless, it becomes much less functional. For Ld 6, there is only a 42% chance of passing the Instinctive Behavior test and acting normally. With the new Instinctive Behavior charts, 29% of the time the units options to act are going to be specifically curtailed, and the remaining 29% of the time it won’t be able to act at all. Further, in the last case, models subject to Lurk or Feed will actively work to remove themselves from the game.
This is a terrible mechanic on several levels. Effects that prevent you from playing with your toys are notorious for easily being unfun (hello, mind shackle scarabs and psychotrope grenades). Yet here we have an army that not only has that effect, targeted at itself, built right in, but even goes so far as potentially remove your own models. It is an effect so harsh that one simply can’t plan to use many units outside of Synapse coverage (and of those you can, several rank among the weaker options, such as Genestealers and Lictors). Which means you have to take Synapse for your army to function at all – Fearless is a minor bonus.
Being so dependent on Synapse creates multiple issues. First is list building: you have to include enough Synapse to not just provide coverage for your army, but to handle loses. Second, it creates harsh maneuver limits during play. Knowing where your Synapse is, and thus where it can go next turn, also tells your opponent where the rest of your army can go. It restricts the utility of faster units like Hormagaunts, Gargoyles, and Raveners, as the ability to move 12-18″ is of less import when doing so would leave the unit out of Synapse (note: these factors make the Flyrant especially valuable, as it is not only dangerous in and of itself, but it’s also very mobile Synapse). Finally, the Synapse nodes are glaring weak points in the army: eliminating a Synapse node not only removes the model(s) in question, but directly and significantly impacts the ability of the army as a whole to function. Units are left out of Synapse and subject to Instinctive Behavior are no longer reliable, and may actually be subject to falling back or inflicting wounds on themselves. And given that Synapse is generally expensive or fragile, maintaining coverage becomes rather difficult.
Thus, Synapse and Instinctive Behavior are not only generally unfun, they are an active disadvantage. The former is bad game design in general, and the latter compounds it as Tyranids pay points for the advantage of Synapse, but do not get a discount for the disadvantage of Instinctive Behavior. That is the key realization I had: a 5 point Hormagaunt not subject to Synapse and Instinctive Behavior is better than the 5 point Hormagaunt that is. Yes, that means they would have to worry about Morale tests – but in return they aren’t shackled to other models to remain functional, and don’t eat themselves if too far from those other models. Not only a fair trade, but the Hormagaunt comes out ahead.
In essence, I am saying 5 points may be reasonable for a Hormagaunt without Synapse and Instinctive Behavior, but is too expensive for one that is. This principle holds for all units subject to Instinctive Behavior, to various degrees. It’s less of an issue for Ld 10 units like Lictors, and especially solo Monstrous Creatures not subject to the “do nothing” results, but is a very serious consideration for Hormagaunts, Termagants, Gargoyles, and Raveners, among others.
Fixing this needs to account for two issues, that interrelate. First is the overcosting, which is easy: make things cheaper and/or better, so cost matches usefulness. Second is the inherently unfun nature of Synapse and Instinctive Behavior, and fixing that involves making it better, which helps accomplish the first goal.
Synapse and Instinctive Behavior is a fluffy and iconic element, but it needs to be more enticement and less (but not no) punishment. What if Synapse gave additional benefits, such as Feel No Pain 6+ or (and?) a special rule based on the unit’s Instinctive Behavior (e.g Rage for feeders, Stealth for hunters? And being outside of Synapse was a -1 to WS, BS, and I? This would provide very strong incentive to maintain Synapse, but not a “you just get to look at your models sitting there” if you don’t. There could also be more severe effects for having no Synapse at all in the board.
At this point, you may be thinking, “But that’s the fluff, deal with it!” This is a non-answer, as the game already compromises on fluff for better gameplay all over the place. After all, by the fluff, one Space Marine would punch his way through an Imperial Guard squad without breaking a sweat. In the game he gets dragged down in a turn or two while inflicting minimal casualties. The game should reflect the fluff, yes, as the setting is part of the draw, but it should never be used to justify bad game design (and mechanics that are unfun are, by definition bad). Fluff should add flavor to the game, as it is used to inspire and justify fun and interesting mechanics. The Battle Focus of the Eldar and Space Marine Chapter Tactics are both excellent examples of the fluff translating into good rules.
As for the Tyranids and adjusting the mechanics of Synapse and Instinctive Behavior, it doesn’t really involve changing the basic fluff. First, we all know that Imperial propaganda tends to over-exaggerate, so “kill a brain bug and all the small bugs just go to pieces” is likely an overstatement. Second, the Hive Mind clearly reaches to the battlefield, as it’s what the Synapse creatures are relaying. So proximity to Synapse focuses the control of the Hive Mind, allowing the other creatures to function more efficiently. Having some Synapse on the table, even when outside of Synapse range proper, still provides an attenuated control. It’s only complete removal of Synapse on the board, representing the presence of no nodes at all in the immediate area, which causes the full breakdown.
This still presents the overall fluff and narrative effect of how Synapse works, and preserves targeting Synapse nodes as an important and viable strategy, but makes the results less stark and immediately swingy. Instead, the effects are more graduated, and allows the Tyranid player to keep using their toys.
So I suggest taking the Tyranid Challenge: find an amiable opponent and try out the same Tyranid list a few times, some using Synapse and Instinctive Behavior, other times ignoring them. I think you will find the results interesting.