Do this in incremental tiers based on size. This idea comes from the fact that fighting in large coordinated numbers has both advantages and disadvantages - not just one or the other. Currently, there are only advantages to being in a really large group - perhaps most notably enormous amounts of healing stacked on top of AOE cap protection. What are the disadvantages of being in a large group, apart from destroying server and game performance? None. This is unbalanced.
My idea for a "battle formation" debuff might look something like this:
- Group of 1-8: No debuff
- 9-12: 5% penalty to healing and damage
- 13-16: 10% penalty to healing, damage, and 3% penalty to movement speed
- 17-20: 15% penalty to healing, damage, and 6% penalty to movement speed
- 21-24: 20% penalty to healing, damage, and 9% penalty to movement speed
The outline above is just to get the point across - there's likely a smarter way of implementing the thresholds / values etc.
Of course this game bears no resemblance to reality - but I think it's still interesting to consider historical examples of large organized armies being countered by smaller, more mobile units attacking the flanks and the rear. I really like the idea of having a game dynamic where choosing to be part of a large team comes along with the sacrifice of personal heroism and strength.
The devs have shown an interest in creating some kind of disadvantage to being in a large group - look at magicka detonation and its morphs, as well as the Vicious Death set. But balance will not be had by way of an ability or an armor set - much the same way sorcerer shields could not be balanced alone by shield breaker. We need a baked-in solution such as what I'm suggesting here.
Large groups need not worry - you will still be able to obliterate most opposition - you will just need to pay a little more attention to what is happening instead of just feeling safe inside the flock.
Reddington James — Magsorc & Magplar (NA PC)