Mercy was once one of the strongest support Heroes in Overwatch.  Able to deal damage with her Caduceus Blaster, heal her teammates or boost their damage, there’s little wonder she’s popular. Although she lacks the mobility of Lucio, she can heal single targets far better than he can. Her Caduceus Staff can heal or boost the damage output of a single Hero and as a channeled ability, similar to the Medic in Team Fortress 2, she offers excellent single target healing. With correct positioning and if she follows behind a Tank (especially Roadhog or Reinhardt) she dramatically increases her team's push potential.  The official Blizzard site shows her as a 1 star Hero (Easy to Play), however this isn't necessarily true: to play Mercy well requires incredible positioning and awareness. 

Unsurprisingly and due to the fact Mercy is almost entirely support based, she’s incredibly limited when she isn’t assisting her team. Although her Caduceus Blaster deals reasonable damage she really can’t survive against most enemy Heroes 1 on 1. Fortunately for her she has two tools that can help her: Angelic Descent and Guardian Angel. The former allows Mercy to dramatically reduce her speed when falling from a height, ensuring she has an advantage when trying to escape others, while the latter allows Mercy to fly towards an ally at speed. Both combined give her valuable means of escape/engagement and if she is caught out of position, can save her life.

Updated: 11 July 2017

Lore

Ziegler rose to become the head of surgery at a prominent Swiss hospital before pioneering a breakthrough in the field of applied nanobiology that radically improved the treatment of life-threatening illnesses and injuries. It was this expertise that attracted the attention of Overwatch.

Because her parents had been taken by war, Ziegler was opposed to the organization's militaristic approach to keeping global peace. Ultimately, she recognized that Overwatch offered her the opportunity to save lives on a much larger scale. As Overwatch's head of medical research, Angela sought to leverage her work for healing in frontline crises. The result was the Valkyrie swift-response suit, which Ziegler herself piloted on many Overwatch missions.

Despite her contributions to Overwatch, she was often at odds with her superiors and the organization's overarching aims. When the group was faced with a series of allegations, Ziegler was interrogated in the hearings conducted by the United Nations. In light of the fight between Overwatch members John Morrison and Gabriel Reyes, Ziegler admitted that the outcome had been inevitable. They had drifted further and further apart ever since Morrison had been chosen over Reyes for the position of strike commander, and that rift has widened despite her efforts.

Abilities

Angelic Descent (Passive) - Allowing Mercy to descend slowly from any height, you might think a trait such as this is bizarre in a game that doesn’t have falling damage. While that’s somewhat right, its purpose is to allow Mercy to jump greater distances or to keep up with Heroes such as Pharah. Combined with Guardian Angel (see below) she can comfortably fly up, glide down and fly back up instead of dropping like a stone. To activate Angelic Descent, simply press and hold the jump button to begin slowly falling to the ground. To end the passive ability, simply let go of the jump button. Finally and as an undocumented addition, her Passive ability also allows her to regenerate health if she doesn’t take damage for 3 seconds.

Caduceus Staff (LMB/RMB) - Capable of firing two types of beam at her allies, Caduceus Staff provides a continuous stream of healing to allies Mercy targets, healing them for 60 hp/s. If she uses her alternative fire she can boost their damage output by 30% as long as she maintains the beam on them. Switching between both beam types regularly is key to playing Mercy as knowing when to heal or boost the damage of an ally can often clinch a fight

Caduceus Blaster - Providing Mercy with her only means of defence, Caduceus Blaster is a rapid firing pistol that deals reasonable damage. It’s more than capable of killing other Heroes, but its low damage (20 per shot compared to McCree that deals 70) makes it much better at finishing off low health players than attempting to bring them down from full health.

Guardian Angel (Shift) - Fundamental to Mercy’s playstyle, Guardian Angel allows her to quickly fly towards an ally she targets. Whether it’s a teammate who’s low health or to simply escape someone that’s trying to kill you, effective use of Guardian Angel will not only allow you to quickly reach allied players but survive when necessary. Guardian Angel also allows Mercy to follow Pharah with ease, as the combination of flying/slow fall allows you to remain airbourne for lengthy periods of time.

Resurrect (Ultimate) - Probably one of the strongest Ultimate abilities in the game, Resurrect allows Mercy to revive dead teammates. As long as they’re still respawning, if she uses her Ultimate ability near their corpse they’ll be brought back from the dead. Considering it brings allied Heroes back to life with full health, it’s more than possible to turn a match around with its use. On a team wipe, instantly reviving everyone - against Heroes that are weakened - is exceptionally strong.

Strategy

When it comes to strategy, Mercy is a healer first and foremost. Your role is to keep your team alive and focus your attention on your front-line Heroes (such as your Tanks) or Heroes that are incapable of healing themselves. Ensuring your tank survives will not only allow them to soak damage and push forwards, but reduces the healing you’ll need to provide to the rest of your team.

As it currently stands there’s only two ways to play Mercy due to how vulnerable she is. The first is to simply stay with your team, keep all their health topped up or to “pocket” another Hero such as Reinhardt and Pharah. Pocketing is when you follow one Hero and bolster their damage constantly, healing them when necessary. It’s particularly effective with high impact, high burst Heroes such as those two named because it allows them to deal eye-watering damage.

Unsurprisingly, Mercy is a prime target for the enemy team due to the amount of healing she can provide, but also because of her ability to bolster the damage of her team. Widowmaker, Genji and even Winston will make it their mission to zone you out or pressure you constantly. The only way to survive is to hope and rely on your team to peel for you. Should it come to it, you can always use Guardian Angel to quickly fly away.

Finally and when it comes to using your Ultimate, it really needs to be at a time where your team will gain maximum value from it. Reviving just one fallen player isn’t usually worthwhile but if that one player happens to be your Tank and the rest of your team are alive and making a push, it could just be.

Matchups

Heroes listed here are particularly challenging for Mercy. While those listed can still be killed, they pose a particularly difficult challenge for him so be sure to take extra care. 

Tips

This list of tips and tricks are just a handful of things we think will help your Mercy play. We'll continue to add to the list as required and if you have any tips you'd like to share, let us know in the comments below and we'll place them here. 

1. In an emergency you should change to your Blaster. Against low health players it can easily finish them off. 

2. You should always give priority to your Tank, especially on Payload escort, but keep the rest of your team topped up when they need it. 

3. Your damage boost is incredible with hard hitting Heroes such as Pharah or Widowmaker. It also works exceptionally well with Bastion and Roadhog. 

4. Guardian Angel is your main leap that allows you to quickly travel to an ally. Whether it's to reach them in order to heal or to escape, choosing the right target and the right time is incredibly important. 

5. Your passive can be particularly value when using Guardian Angel as it allows you to fly high but descend slowly - alternating both can keep you afloat. 

6. Your Ultimate ability is best used on a Capture Point or next to a Payload when multiple allies have fallen. Try to position yourself where you'll be safe as it causes you to remain immobile when being used.

7. Try to encourage your team to work together. If you're on defence, have Reinhardt and Bastion setup together with you. The three combined are absolutely hellish to fight again. 

8. As Support and when healing (or damage boosting) you're a second pair of eyes for the Hero you're looking after. Be sure to look for threats, position yourself to reduce risk from them and warn your team of the danger. 

9. Your resurrect ability (your ultimate) resets Guardian Angel allowing you to fly in, resurrect and fly out immediately to an ally. 

10. You can cancel Guardian Angel by pressing it again. 

11. You can cancel your resurrection animation by pulling out your pistol.   Take advantage of this by firing on enemies as your allies come back from the dead. 

12. Stay with the group.  Flying off to help the lone wolf player only puts you in a position with no escape route.  

13. When boosting a Pharah, remember that your boost affects the rocket on impact, not when it is fired. 

14. Only use Resurrect if it will give your team an advantage.   Rezzing into more deaths is a huge no-no. 

15. Only use Resurrect if the location you are rezzing into can be held. 

16. Turn "Toggle Guardian Angel" off in Mercy's Personal Settings > Options > Controls.   This will allow you to hold Shift and fly immediately as a teammate comes into line of sight.   It also allows you to stop flying by releasing the Shift key.   

17. Hiding makes sense if you are going to lose the fight, but... don't hide in a 50/50 team fight.   You just give the other team a 5v6 opportunity, which you will then rez into.   Your stream of healing is powerful.  Use it. 

18. Pharmercy is powerful, but don't permanently attach yourself to her.  You are part of a team.  

19. Don't rez if your team has already won the fight. 

20. If your team is going to die, let them all die at the same time.  Topping off the tank just to watch the critically injured DPS die is just poor play. 

21. You can kill Torbjorn’s turret with your Blaster from outside of his turrets range.

22. Be careful when using Guardian Angel as it can sometimes put you in a worse position if it causes you to over-extend.

23. You do not have to constantly look at your ally when casting your beam at them. As long as you hold the button down and you’re near them, you can look around for dangers.

24. When low health find cover and allow your Passive to regenerate your health.

Skins, Emotes, Victory Poses and Voice Lines

Extra Learning 

Analysis, Positioning and Decision Making

How To Stay Alive as Mercy

Top 500 Player (Binky) Mercy Guide

Yajji's Grandmaster Mercy Guide

Blinky's Positioning and Rez Guide

Master's Guide to Mercy

Grandmaster Mercy Tips for Hanamura

Top 50 NA Guide to Mercy