Rainbow Six Siege is not a game for the faint of heart. It's an intense, nerve-wracking game that requires patience, intelligence, and plenty of thought. If you happen to be new to Siege, it's likely that you're dying. Like, a lot.
It's alright! It happens to everybody who comes to the game, partly because of the inherent learning curve of a game like Siege, and partly because you're probably playing against people that have been playing it for years by now. There's a lesson in every death in Siege; if you're paying attention and apply the new knowledge, you're going to be getting better every single time you die. That's why Siege is so rewarding and so exhilarating! So, let's take a look at some of the reasons that you're (probably) dying:
10 10. YOU AREN'T BEING A TEAM PLAYER
Not everybody has friends to play with in Siege, leading to you getting a random assortment of new teammates every match. Heck, even if you have friends you play with on a consistent basis, it doesn't mean you're all meshing as a coherent force. If you have the opportunity to communicate with your team, try and compliment each others operator picks. Did your teammate pick Thermite? Bring a Thatcher, Maverick, or Twitch to help them out; things like that.
Once in the actual round, watch each other's backs! Newer players often have trouble on Attack, and get ambushed by roamers often. Keep an eye on areas an enemy could come around to flank while your teammate clears the areas ahead of you.
9 9. YOU DON'T KNOW THE MAPS
The tough thing about this problem is that the only cure is time. You aren't going to understand the maps, where people can (and likely will) come from, or any of the most useful angles until you've spent some time in them. Running around the maps in Terrorist Hunt or in a Custom Game can help you a little bit in this department, but it isn't going to do anything to help you recognize the areas that other players are likely going to be hanging out in, or show you many of the areas that are going to be useful to you.
What you can learn in Terrorist Hunt is vertical play. In Siege, many of the ceilings/floors can be shot through, giving pretty wide kill-holes you can see up and down in. Break different floors and ceilings open in Terrorist Hunt, and make note of what floor is above/below you; it's going to be a big help in PvP.
8 8. YOU AREN'T USING YOUR UTILITY
Every Operator in Rainbow Six Siege gets a couple of gadgets. One of them (unless you're playing as a Recruit; don't do that) is the special gadget that only the operator you selected has access to. The other one is a gadget that a few others operators have, be it a smoke grenade, flash grenade, breach charge, etc. as an Attacker, or barbed wire, deployable shield, impact grenades, etc. as a Defender.
As an aside, Attackers (and Mozzie and Echo) all have drones. They are some of the most valuable sources of intel and Siege, and should be used, often.
7 7. YOU AREN'T USING YOUR UTILITY CORRECTLY
The way these gadgets are used is almost always going to make the difference between winning and losing in Siege, and a lot of new players don't often know exactly when or how they should be using them. The best advice is to just... use them. Try the stuff out, see what they do, how they work, and over time, you'll get comfortable with them and start seeing some more success.
6 6. YOU AREN'T SOFT BREACHING
In Siege, there are a few different types of walls. There are impenetrable walls, that do not change at all throughout the round. There are soft walls, which are walls that bullets can penetrate and eventually open holes in, breach charges can blow through, and so on. Those soft walls can be reinforced with metal reinforcements by Defenders, requiring the use of Thermite, Hibana, or Maverick to blow/burn open.
A lot of new players don't realize the importance of using soft walls to your advantage. Getting a kill on people behind a soft wall is one of the safest and easiest kills you'll ever get, and opening up rotation-holes through soft walls is a great way to get into an area from a direction the enemy may not expect.
5 5. YOU AREN'T WATCHING OUT FOR RUNOUTS
Let's, all of us, just this once, be honest here. Runouts are irritating. Yes, they are perfectly fair, and no, nothing about them needs to be changed, but no one is ever madder about getting killed than they are when they get killed by a Defender running out of the building and gunning down unwitting Attackers.
Luckily, as an Attacker, you can be (somewhat) prepared for it. If a Defender is outside the building for more than two seconds, they'll be marked on the screen for all of the Attackers to see until they go back inside. There are a ton of Attackers that have claymores, and a well-positioned claymore outside a popular runout spot is something a Defender either won't be able to see until it's too late or something they'll need to waste an explosive to get rid of. Nomad is an operator that can be helpful in this department too; her gadget will knock Defenders back, giving you ample warning of their presence, and likely wasting the two seconds the Defenders have before they'll be tracked.
4 4. YOU'RE PLAYING TOO FAST
There are two types of new players. One of those types is the kind of new player who plays way too fast. On Attack, they rush into the building and sprint towards the objective, usually dying before they make it more than fifteen steps into the building.
Unless you're doing this with the rest of the team right behind you, you're making a mistake. Yes, this is occasionally going to work out when you catch the Defenders off-guard and get you some easy kills. But more often than not, you're just serving yourself up on a silver platter and making the job a million times more difficult for the rest of your team.
3 3. YOU'RE PLAYING TOO SLOW
Equally as disastrous as playing too fast, playing too slow means the rest of your team is having to do all of the work while you creep your way through rooms without really doing much of anything. If you're always the last one alive on your team, you should probably take a look at the way you play, and make a conscious effort to try and keep pace with your teammates, helping hold angles and push when needed.
2 2. YOU AREN'T USING OPERATORS THAT PLAY TO YOUR STRENGTHS
Everybody has something that they're better at doing in Siege than other things. Maybe you're the person who's great at getting relevant information out quickly and concisely! If that's the case, you shouldn't be playing operators like Bandit or Ash; you should be playing Operators like Valkyrie, Maestro, or Dokkaebi. Or, perhaps you're the player who excels at getting angles on the enemy that they don't expect, leading to some easy flanking kills! If that's the case, don't play operators like Castle or Montagne; play operators like Caveira, Vigil, or Nokk.
This isn't to say that you should limit yourself to one kind of playstyle, but when starting out, it's easiest to learn one kind of playstyle and get comfortable with it before jumping around to another playstyle.
1 1. YOU'RE STILL DEVELOPING YOUR GAME SENSE
You're going to hear a lot of references to "game sense" from players. The mystifying, ethereal, game sense.
All game sense really means is a general knowledge of mechanics in Siege, and a good feeling of what the enemy team is going to do before they do it. Once you've got a healthy amount of playtime in Siege, you're going to recognize tactics and playstyles. With this, you'll have a good idea of what the enemy team is likely trying to do, or what you or a teammate should be doing in order to have some success. As quick as Siege plays, this feels almost like a sixth sense, or a Spider-Sense, and you'll start doing things based on feeling rather than coherent thought.