- Security Guards - They can be easily identified, found in most areas, they are armed with SLP .40 pistol.
- Bodyguards - US State Department Special Agents assigned to protect Delahunt, can be found in and outside of Delahunt's room, and guard the rear area of the stage. The ones that are with Delahunt have MP5, the rest have SLP .40 pistol.
- Both of the targets are unarmed.
Kill Alvaro D'Alvade
- Note: By using this method, you can kill Richard Delahunt immediately (see below) after Alvaro D'Alvade, thus, it is the easiest way to earn Silent Assassin rating.
Note: Using this method will cause the guards to "delay" their response to Alvaro's death, for about 15 seconds. Unfortunately, if you are in the room when it happens, there is a risk that the guards get alerted and blow your cover.
Equip and upgrade your sniper rifle. It's recommended to use the silencer or low velocity ammunition. The only safe place to take the shot from is the light control room, which is in the middle of the third floor with a keycard lock. The Keycard can be found in an office on the second floor in the western-most part of the map. With the rifle ready and aimed at D'Alvade, wait for the actor to take the shot with the prop gun, and shoot D'Alvade in the head.
Although the silencer is not needed to take out D'Alvade, strangely, during this time everyone will ignore the gunshot. You can also shoot Delahunt from the light control room when he comes running from his booth and goes to D'Alvade's body, but there is a risk that a guard will enter the room and expose you if you have the rifle out.
One way to kill both targets is to get the worker outfit in the bathroom as soon as the game starts, sneak into the back area and climb the shaft to the back of the stage. Throw a mine onto the pole behind the rehearsing target. Before he can react, silently shoot him in the head. Nobody will see you. Swiftly make your way to the front of the stage and as soon as the other target has reached the dead one, blow the mine. This will give a "Ghost" Ranking but it is a quick and easy way to do it.
Another way is to sneak into D'Alvade's room and leave a bomb behind the curtain in front of the mirror, wait for him to get in front of it and rehearse and then detonate the bomb, killing him. It's a good idea not to place it too close to the mirror since the blast might go through the wall and kill the bodyguard outside, which will affect the rating.
If you have a second AP-mine, you can place it in a toolbox taken from a worker, then casually drop it outside Delahunt's door. Detonating it will kill Delahunt along with most, if not all, of the security team with him.
Falling Lighting Rig
On the upper floors, near the area holding up the chandelier, there is a location above the stage where 47 can place a bomb near a wire holding up a piece of scaffolding. When D'Alvade takes his position on stage, the player can detonate the bomb and cause the scaffolding to fall down on him, making it look like an accident. It's advisable to knock out the worker who walks around the area and drag him to safety before detonating the device since he might get caught in the blast (he can also be pushed off a railing as an accident kill). The same trap can also be used to kill Delahunt if the player kills D'Alvade with the real WWI gun or the sniper rifle, since he will go to D'Alvade's body if he sees him die.
Falling Chandelier and Lighting Rig
During later replays, it's possible to use two RU-AP bombs to take out both Delahunt and D'Alvade. With a disguise, go up to the rigs and make sure all bystanders are out of the way. First place a bomb at the lighting rig and kill D'Alvade when he is in place. Then quickly place a bomb at the chandelier rig, watch the minimap for Delahunt's location, wait for him to run into the opera room and trip and detonate it. If you put out both bombs at the same time, they will detonate simultaneously and make the chandelier fall down prematurely.
Take your favorite weapon, preferably one with some firepower and a lot of capacity. Walk up to the stage and draw your weapons. Shoot Alvaro down and make your way out of there to find a good hiding spot, as all the opera guards and Delahunt's bodyguards will come after you, trying to avenge the murder.
Another option is to walk into the theater draw your weapon and quickly shoot the lock on the door guarded by two men at the top of the stairs, once this door is opened throw a mine onto the balcony on the other side then detonate, that's the end of Delahunt and his bodyguards. As soon as this is done quickly make your way to the stage and through the left hand door, down the corridior to Alvaro's dressing room quickly dispatch him and swiftly make your way to the front door... job done. Estimated finishing time 1 minute 13 seconds.
Alternatively, if you use the SMG Tactical outfitted with a scope, you can kill Alvade and then turn around to snipe Delahunt. DO NOT attempt to rush the exit. Instead, kill both rehearsal gurards and get yourself situated behind the stage. The guards are unable to flank you and will come to you in two's or three's, and in about 3 minutes you will have dispatched all you advesaries with minimal ammo wasteage.
Note that if you follow this meathod in all difficulties above Normal, your Notoriety will increase: thus, making you vulnerable to civilians in the next missions unless you pay to have it lowered.
Should you want to kill D'Alvade with a weapon instead of an accident, his dressing room is an extremely simple method. Just hide in his closet while the rehearsal is still going on and wait for him to enter his dressing room to practice in front of his mirror. He can see your reflection, but shooting out his mirrors will solve this problem.
Note: This is definitely not the easiest way and will make it very difficult to stealthily kill Delahunt. Should only be used if you want to kill D'Alvade with a close range weapon, as that is nearly impossible to pull off during a rehearsal.
Kill Richard Delahunt
Death from Above
This method only works if you use the WWI gun to kill D'Alvade. After swapping the prop gun with the real one, make your way to the walkway above the stage. Once there, you will find a room with the machine holding the giant chandelier in place. Place your bomb on the machine and make your way to a place where you can see the rehearsal. It's a good idea to sedate or knock out the worker in blue overalls who patrols the area, since the bomb blast might kill him. Once Alvaro has been killed by the actor, Richard Delahunt will come running down to mourn the loss of his best friend. On his way to the stage, he will fall down. This is the moment to detonate the bomb, causing the chandelier to crush Delahunt.
You can also plant a bomb on the lighting rig above the stage and wait for Delahunt to run over to Alvaro's dead body. In a way, doing so is easier since it requires less timing.
A more intricate way of killing Delahunt is to climb up with a silenced sniper rifle behind the set from the basement while the workers are looking away; if they spot 47 climbing, they will alert the guards and blow his cover. Put the rifle together, walk up one of the leaning boards holding up the wooden wall, take aim at Delahunt and fire.
If you have a suppressed pistol, you can climb to the scaffolding on the third floor from where the chandelier is being held up, giving you a fairly clear shot of Delahunt. Between rehearsals, he will get out of his seat and lean over the railing. When he does, 47 can shoot him in head and climb up again. Timing is crucial here since there are police officers who patrol the rooms on the second floor. If you use Magnum ammo and a good silencer, you can aim at Delahunt while he's seated through a crack in the floor boards on the scaffolding and shoot through the floor, but this will lower the rating since the bullet isn't counted as actually killing Delahunt. Also, from the edge of the scaffolding a mine can just barely be tossed into the box (and from his seated position Delahunt will be within its range).
You can only escape the opera through the front door, the same door you used when you entered the opera.