There are 75 operators in Rainbow Six Siege X, where each one has its own weapons, gadgets, and strategies. This guide will focus only on the top 10 operators that will make your game so much more efficient and enjoyable.
Mira
The best defending operator in the game is none other than Mira. Her Black Mirror device allows you to see through obstacles, which is why placement is so important. Put both mirrors above the sections of interest and use Nitro Cells to blast opponents. But look out for attacker gadgets that can effectively prevent Mira from using her mirrors. For this reason, it's recomennded to pair Mira with either Mute or Bandit, as they can protect mirrors from being destroyed. Another way to keep Mira's mirrors intact is to use Azami's barriers.
Of course, one must have a very good knowledge of any given map to utilize Mira in the best way possible. Once you deploy a mirror, it cannot be removed or replaced, so keep this in mind when choosing how and where to place it. Also, use fire extinguishers and gas pipes to your advantage when placing mirrors, creating invisible traps for opponents.
Bandit
If you like setting up traps, but Mira's strats are too complicated for you, then the next best option would be Bandit's Shock Wires. Of course, you can combine their powers and use wires to protect Mira's Black Mirrors. But you can connect the wires to any metallic gadgets and send an electric shockwave through them, seriously damaging any opponent coming in contact with them. This strategy works exceptionally well against enemy drones, especially when combined with Mute's Signal Disruptors.
In case you want to insta-kill an opponent, then connect a wire to Frost's Welcome Mats, and once an enemy steps on them, they'll get instantly eliminated. But you have to be careful, as gadgets like EMP grenades, shock drones, and electronic scanners can easily detect and disarm Bandit's wires. So connect them only right before your opponents can get into a trap.
Doc
There's probably no need to mention that every team in Rainbow Six Siege X absolutely requires the Doc operator, who can heal and revive allies from a distance. The only other alternative that you could opt for is Rook, who grants allies defensive plates. Although they greatly reduce incoming damage, they can't protect you from being killed. However, if the safety of your operators is really important to you, then combining both Doc and Rook can be extremely effective.
However, there's one operator who can't be healed with Doc's stim pistol, and that's Skopos. So if you have Skopos on your team, it's still better to just take Rook instead. In any case, Doc can also use other offensive weapons, such as MP 5 or SPAS 12. This allows him to stay on top of the game, becoming one of the better mains in the game.
Mute
Sometimes you just can't get rid of all the drones and breach charges on a map, and that's where Mute comes into play. This operator jams these gadgets using Signal Disruptors. This opens up a window of opportunity for your team to push forward with their plan and find the objective. Note that in the preparation phase, Mute is especially important, disrupting enemy scouting. The best places to place disruptors are at the doorways.
Pair up Mute's disruptors with Mozzie's pests. While Mute jams enemy drones, Mozzie can hack them and use them to your advantage. Note that this is an advanced strategy and requires mastering the interactions between these two operators. Also, remember that Signal Disruptors work only on electronic gadgets and will not affect the mechanical ones. The range of a disruptor is also limited, so be sure to determine the area of effect before placing it on the floor.
Mozzie
This operator is capable of hacking several enemy drone kinds, such as yokai, shock, kludge, and ground recon. Shock drones are the best targets, as they can be used to surprise attacking operators, turning these drones against them. This kind of distraction tactic is really effective right before the assault phase. Another fun way of using Mozzie's pests is not to shoot them at drones but to set them up as traps, waiting for the drones to fall under their influence.
What's really important here is that only Mozzie player will know if the droid has been successfully hacked, leaving opponents in the dark. They'll know it only if they decide to control it, which, of course, won't work. But by that time, you'll be in full control of it, capable of using its cameras for surveillance and already establishing a working strategy on the go.
Valkyrie
Surveillance is truly everything when it comes to the preparation phase of any matchup. That's why Valkyrie's Black Eye sticky cams are so useful. You can throw them at the ceiling and monitor everything that happens in the vicinity before moving in and out of the visible area. This simple strategy allows you to not only keep yourself from harm but also cover others' backs. The Black Eye cameras are also much more useful than, say, CCTVs, which can't see everything.
On top of that, if you wish to change the placement of the cams, you can just as easily detach them and reposition to another section of interest. Be sure to use their gyroscopic characteristics and move the eyes to see everything within 180 degrees. The monitor allows you to distinctly see an enemy passing through the visible area, making it so much easier to prepare yourself and your teammates for combat.
Buck
Here's arguably the best attacking operator in Rainbow Six Siege X due to his Skeleton Key shotgun, which is the most powerful shotgun in the game. It has a surprisingly low recoil for a shotgun, but it's powerful enough to destroy walls and other similar obstacles. There's no need to mention what it'll do to an enemy operator at close quarters. By the way, if you want to make a larger hole in the wall, simply step back and allow the shotgun pellets to spread out wider.
Players who main Buck often use his shotgun to destroy gadgets hidden under the floor or above the ceiling. It's also a highly effective strategy to just wait out a running opponent and take them out while they're passing across the hole. The only drawback of the Skeleton Key is a quick bullet drop, which already begins at 14 meters.
Sledge
In case Buck's shotgun seems a bit too loud for you, then the next best option for removing obstacles in your way would be Sledge's hammer. Although the destruction levels are equal to explosives, the hammer hits produce almost zero noise, which makes it so effective for stealthier strats. It also has enough power to insta-kill an opponent, although you do need to stand very close to the target for it to be effective.
The only thing you must watch out for when destroying walls with Sledge's hammer is the canisters with fuel nearby. If they explode while you're breaking the wall or the floor, the canisters may explode right in your face. Experienced operators know this trick too well and specifically set up these kinds of traps against unsuspecting Sledge players. But if you have solid scouts on your team, they can detect such traps and warn you in a timely fashion.
Jager
One of the biggest threats that comes from attacking operators and consistently disrupts matchups is the live grenades being thrown at the most inconvenient moments. If you're tired of getting constantly bombarded by these grenades, then use Jager's magpies, which disarm grenades right before they explode. Jager can also intercept other explosives, such as projectiles, breaching rounds and pellets, stingers, lances, and many more types. Just make sure that your ADS is within the range, which in this case is 5.5 meters, or the explosion will destroy your gadgets.
If you strategically place your ADS, it'll be able to repeatedly disarm explosives, with just a 10-second cooldown between each disarm. However, careful players may quickly detect magpies and feed them useless grenades before throwing a more potent explosive at the enemy. If this happens, then you have no other option but to reposition and place another ADS, hoping it won't get detected.
Hibana
Not to be overlooked is Hibana, an offensive operator who is capable of successfully demolishing reinforced walls — a skill that only a select few operators in Rainbow Six Siege X possess. This is possible due to Hibana's pellet launcher X-KAIROS, which is by far one of the most useful gadgets in the game. The only drawback of this weapon is that it takes a few seconds before the pellets melt through the reinforcements. Experienced players can use this short window to shoot the pellets, preventing them from destroying reinforced objects.
The only other operators that can destroy reinforcements in this game are Thermite, Ace, and Maverick. They all have their methods to do this, but Hibana's pellets are the most reliable. However, it is actually recommended to combine Hibana with Maverick, who can provide instant sight lines in a reinforced wall.