Random Arenas is usually the first PvP area players try out. Yet it is also a difficult one. Most players will consequentially lose fights and get shouted at early on, disencouraging them from playing PvP anymore. This is a big problem in the PvP world. This post might help you avoid this problem .

0) Quick guide for the lazy man (or woman)
*make full use of the PvP armor you can create
*Res sig is obligatory unless monking
*take at least 1 self healing or self defence skill; maximum 2-3
*good builds include damage, healing and spreading conditions/hexes. DO NOT TANK.
*Try not to take a defensive elite skill.
*Do not get disencouraged by flaming.

*Common mistakes include (don't make these):
**volley/barrage + a preparation
**taking 2 or more preparations
**using a tanking elite (eg. Defy Pain)
**using frenzy and healing signet at the same time
**using frenzy without having a cancel stance in your build
**W/Mo or A/Mo characters with mending, healing breeze, patient spirit or Word of Healing
**healing characters who specifically ask not to be healed. ALWAYS do what a player asks you to do. He might have an exotic build you did not think of, and if he's a bot or leecher healing him doesn't do good anyway.

1) General Setup
You are randomly teamed up with 3 players against 4 other players. There is no way of choosing who you play with or against (well, not that you should know of for now :p), making luck a key factor.

Statistically you will lose more than half of the times you enter the first round. This is mostly beyond your power and it can hardly be influenced.

2) Builds
Unless you are playing a healing build, the skill resurrection signet is almost obliged to be in your skill bar. It is relatively quick, and resurrects your friends to 100% health. Both these things are most key in RA.

You'll want to last a bit. Self healing or protection is important. You should however priorize defensive skills above healing skills. Popular defensive skills mainly include blocking skills (Distortion, Magnetic Aura, Frenzied Defense), though applying conditions on foes attacking you can be good too (eg. Blind, Dazed, Weakness, Crippled on meelee characters).
Self Healing is very popular, but less effective.

Condition Removal is a key part of fighting too. Antidote Signet, Sight from Beyond and Mending Touch are popular choices to keep you protected from shutdown conditions.

Also keep the main goal of your build in mind! Many players make the mistake of taking a Defy Pain warrior to random arenas. Defy Pain will keep them alive for a long time, but it will seriously decrease their damage output. The ennemies will ignore them, kill their teammates and then attack them. Tanking ISN'T a good tactic in RA.

3) Equipment
High Health is advisable.
Multiple Weapon Sets are advisable. Casters should consider taking a standard weapon, then a wand and offhand to give them +30 energy but -2 energy regen, AND a defensive set (spear with health +30, energy +5, random thing; shield with health +30, received physical damage -5 (20% chance)).

4) Tactics
If you have a healer in your team, stay within earshot of him. Don't run away from him.

Different targets have different priorities. Healers should be taken down first, then shutdown squishies (usually mesmers and necros :p), then offensive casters (usually elementalists), then assassins, then rangers and dervishes, then warriors. BUT, it can be wise to spread damage over multiple targets too, as it makes is harder on the ennemy healers.

Shutdown skills (interrupts, conditions, certain hexes) should be used against ennemies that are big threats. Generally, this means the assassin bashing on your monk.

If you see something suspicious (eg an ennemy with VERY low health before the battle has started), stay away from it :p[b]