Viper

Basic Information
"The Viper is the fastest moving vehicle on any battlefield. The Viper is lightly armored and somewhat less agile than similar Axon counterparts, but it compensates for this with one of the most destructive attacks of all Necris vehicles. It can literally launch itself at a target, converting all its momentum and power into a single armor-penetrating impact.

As the Viper rises into the air, two articulated stabilizers unfurl to reveal the anti-gravity fuel cell that controls vehicle movement. It momentarily hovers while it locks on to a target, then simultaneously ejects its pilot and launches itself forward with fully destructive intention.

Its conventional armament includes front-mounted cannons that launch spheres of rebounding plasmid energy. They are not particularly lethal, but their high rate of fire and ability to ricochet around corners makes them effective nevertheless."

- UT3 manual

Using the Viper
The Viper is the fastest vehicle in the game. It's not as agile as a Manta, so hit-and-run kills are a little harder when the target player manages to dodge the incoming Viper. Its primary guns fire bouncing plasma bolts that can do quite some damage if aimed correctly.

The Viper can jump and briefly hover in mid-air, which also is the preparation for its self-destruct mode. When activated, the driver is ejected and the Viper launches itself at its target. It detonates on impact, causing massive damage. Many smaller and medium-sized vehicles and turrets can be destroyed with a single hit, including Nightshade and Nemesis. A successful kill with the self-destruct mode gives the player a "Bullseye" reward. However, if the launched Viper is destroyed before impact, the player hears "Denied". If the launched Viper was destroyed by a Goliath or Paladin, the tank driver gets the "Eagle Eye" reward.

Going against the Viper
A single well-placed AVRiL rocket can easily take out a Viper. If you're on foot and don't have the AVRiL, you can try your luck with the Impact Hammer's EMP mode. It will push back the Viper and severely damage it.

In a Darkwalker you can use the secondary "horn" attack to push the driver off the Viper.

A Scorpion also kills a Viper pretty fast, since the Scorpion's shots home into the Viper.

Vehicle CTF strategy
The Viper can be a very useful vehicle for assisting flag runners, due to its speed. It's also good for quickly cutting off an enemy flag runner, and its fair amount of agility will help you to get to them.

It is also useful for eliminating high-priority targets, such as enemy Goliaths.

Warfare strategy
Much like in VCTF, Vipers can give Orb carriers a trip to the next node, greatly expediting their trip and allowing for a quicker offensive pace. They're also great at taking down enemy nodes, as the Plasma balls do fairly good damage and when the Viper is damaged enough the driver can kamikaze the node, doing a great deal of damage to it.

It can also be very useful in tight corners of maps, where the balls can bounce around in the cramped quarters and potentially strike some enemies.