Playing as Zarya
If the enemy team has a Reinhardt and his charge connects with one of your teammates, use Projected Barrier just before they hit a wall- the charge does a lot of damage, increasing the damage of Zarya's Particle Cannon (Her left-click) as well as potentially saving a teammate.
If you put a particle barrier on Reinhardt, damage absorbed by his shield will power up your Particle Cannon.
You need to be with your team at all times with zarya. Spam her barriers in firefights as much as possible to charge up your main weapon. Fully charged it's quite devastating. Be right in the action during KOTH matches.
Her activated shields only have 200 hp, but they prevent all overflow damage (from a single source), making it a great counter to some ultimates (junk rat tires, D. Va ults, high noon, etc)
When aiming her main fire, use the center of the reticule rather than the apparent location of her beam. The beam is just visual, you will always hit the center of your screen.
Active health view of your team mates , avoid shields wastes
Use Graviton Surge to keep enemies away from objectives if time is running out.
You can grenade jump with your right-click to escape Mei's ult
The key to playing Zarya well is predicting your enemy's shots. You have to cast the barrier as the enemy is shooting at you or your allies, rather than before or after. Too soon and the barrier will be wasted, too late and you or your ally will take heavy damage. When timed correctly the barriers will not only extend you and your teammates' life but power up your Particle Cannon to obscene levels of damage.
Zarya may be a tank, but her projected barrier can be used on allies in a pinch to give them some extra survival.
Pick Zarya against McCree and use your shield to really mess with him mentally. "Is she going to shield right away, or not...". Once you have charge and your shield up, overextend and delay the shield...this vaporizes the cowboy.
Timing the shield correctly makes the difference. Don't enter the battle with a casted shield, wait until you start being focused so as the enemy team can't react properly. You'll have the surprise factor and extra damage.
Zarya's activated shields also blocks some CC effects like Mei's freezing and McCree's stun. Against Mei, wait until you're close to freezing to maximize how long it takes to freeze you. Also shield allies that she's trying to freeze so they can get away.
Zarya's ultimate can be devastating with other characters ultimates, like Mei's Blizzard and Tracer's Pulse Bomb. Try to synergize with your teammates to pull off ridiculous combinations!
You can easily take out hostile Reinhardts if you have an ally Reinhardt to team up with. Wait until your Reinhardts shield breaks then shield him and use your left-click on the enemy Reinhardt getting behind him if possible. When you shields are about to deplete pop your self shield and finish him off (your Reinhardt will likely be hammering him at this point). If something goes wry, simply retreat behind the shield. You can aways use your self shield to survive if your careful. This is something you can do repeatedly with little risk with correct positioning.
You can use your spray paint to assist in aiming your ultimate at a specific location. For example, you can use it to mark a spot that can possibly pull the enemy team off the map, and use it accordingly.
Physics attacks ignore the shield , take care
Playing with Zarya
Physics attacks ignore the shield , take care
Try to stay in front of Zarya, she is very difficult to use when she has to turn around to barrier her teammates.
Tell her your ultimate charge. If you have a suitable ultimate such as dragonstrike, first take a look at the scoreboard to see if Zarya has Graviton Surge ready.
If you have her shield on you, be sure to not stay under ennemy fire for too long, it is very short.
Playing against Zarya
Many heroes can escape Zarya's ultimate with a mobility ability. Examples include D.Va boost, Mercy guardian angel, Genji swift strike, Winston jump pack and many more.
Avoid clumping up in choke points, you're setting yourself up for a devastating Zarya ultimate, which could potentially be comboed with Hanzo, Pharah, Junkrat, etc for a team-wipe.
Zarya has very limited range. Try to poke her to force her to use her shield, then kill her after. Mobile heroes like Tracer or Genji work well for this.
Junkrat is Zarya's best friend when the Junkrat is on the other team. Most Junkrats spam their auto's and feed Zarya her charge. If you are playing Junk against her, do your best to not hit her shield, or one of her allies.