The ELF has always been the odd man out. It is a strange weapon, because unlike the rest of the Tribes weapons, it doesn't deal damage. Instead, it attacks energy resources - a unique and bizarre ability.
An ability, one might note, that indirectly trumps one of the philosophies of game design - freedom of movement.
But in my mind, that doesn't necessarily make it a bad weapon. In fact, I'll argue that one can design a good ELF. Then I'll explain why I *still* consider it a mediocre addition at best.
The ELF actually served two purposes - the first being more important than the second. It drained player energy, but it also drained turret/vehicle shields! These two abilities are seperate ends reached by the same means, and so I'll discuss the weapon as viewed from three angles: purely anti-personal, purely-anti-shield, and the legacy hybrid version.
A purely personal ELF gun.
To me, the T2 ELF gun fell mostly along these lines. It attacked a player's energy, tracked them easily, and did so without damage to the ELF user. It was also overpowered.
Why? What makes it overpowered? Well, firstly:
1. It gives a large disadvantage to the enemy without giving a disadvantage to the user.
2. It has infinite ammo.
3. It works at safe but effective ranges.
4. It aims itself.
We can attack the ELF and attempt to balance it by going after any of these four strengths. By turning one or more of these advantages into a weakness, we can hope to balance the extreme movement advantage the weapon gives.
Point 1: This point could be turned disadvantageous by draining user energy, such as in T1. The only problem being that if the range is too short, the energy drain might affect the user more than the enemy. This could become too disadvantageous. But that isn't too large of a problem.
Point 2: The weapon could use an ammo such as a "batteries" that is drained and lost when used.
Point 3: The weapon's range could be shortened. Unfortunately, you're actually relatively safe at close range in the first two Tribes games. So this isn't actually that big of a disadvantage.
Point 4: The weapon's aiming cone could be shrunk to a tiny sliver that must be tracked very accurately to actually drain an opponent's energy.
Some variations on this ide
Points 2 and 4 could be combined to create a "beam" that destroys player energy. This beam could have very little ammo, making it only effective for the very skilled.
Points 1 and 3 could be combined to make it into the T1 ELF. It isn't a particularly useful weapon, but it is effective against players.
But I don't particularly like these possibilities because they still suffer from the biggest problem of the ELF - the undodgeable nature of it. Very few Tribes weapons are directly effective (chaingun, sniper rifle), and these are HEAVILY restricted in some fashion to make up for their powers.
Solving the problem Gandalf's way:
This is actually one of the best reccomendations for an ELF weapon I've heard. It fires an emp burst projectile. This is effective but dodgeable, and restricted by ammo! Good work Gandalf!
At the end, I'll explain why *I* wouldn't include it, but Gandalf's idea is the best anti-player implementation.
Anti-shield ELF:
This would be a magic ELF weapon designed to destroy shields. Lacking detail about T:V design, I can't say exactly how this would work - or if it would even be necessary. Things might merely have a lot of health, and very little shielding.
But in theoretical land, this ELF gun would only lock onto shielded targets, disrupting them. This is a bad idea because it hard-trumps a game mechanic, but it isn't a particularly terrible idea either, since it would play a niche role well outside the mainstream gameplay.
The hybrid ELF gun:
This is an anti-personal ELF gun that actually drains from vehicles fast enough to matter.
Why I think the ELF gun isn't a good idea, no matter how you balance it:
The reason someone wants to use an ELF is obvious. They wish to make it easier to deal massive amounts of damage to the enemy player.
My problem with this is that in my mind, only the overpowered ELF gun is worthwhile. A balanced ELF gun is only damaging jetpack energy - a lack that can be overcome by skiing and disc jumping. To me, this means any other weapon would be more effective: from a disc launcher fired at the ground, to a chaingun/flamethrower in the air, to really anything else.
It is precisely because the balanced ELF is the odd-man out that I feel it isn't worthy of inclusion. Every other weapon directly contributes to the death of the player. The ELF either completely ruins the movement model by being overpowered, or it just temporarily harrasses and otherwise unhurt player.
Any way you look at it, it becomes a fringe weapon that exists well outside the normal gameplay model. As in T1, where the ELF is balanced, the balanced ELF gun will not see much use from anyone but enthusiasts for its gimmick or highly skilled players who would rather ELF than use a more efficient weapon.
That's my three cents, take it as you will.