1. Reroll your starting character until you get good perks.

The start of Hard Bastard on Ironman is the most difficult part, a lot of it relies on your luck and rng, so there isn't anything wrong with restarting a couple of times until you get a good starting perk.

Here are top tier perks from my experience:

- Less oxygen consumption. This is the most essential one. On certain ships you'll have less than a minute without oxygen upgrades without this, and honestly running out of air is going to be one of the biggest concerns with this difficulty, so securing this one is a must!

-Being able to see enemies/security on the map. Go with the Sixth Sense one, because it allows you to see both enemies AND security elements! The other perk that allows you to see only enemies is a downgrade from this one.

-Being able to carry a random 4th weapon (if you have one) with you. Ammo is scarce, and carrying 3 guns is not always optimal and sometimes you will need just more firepower, this is literally the most op perk in the game as it would allow you to randomly bring 33% more firepower with you.

- Silent running in combination with Sixth Sense is an alternate method if you want to go more stealthy.

Those are the best possible set up, but you could always swap one for extra health perk at the start, or being able to pick up nearby things automatically (helps greatly in maps with bad visibility or when you're in a rush), and silent running.

2. Don't rush. Don't waste ammo.
You'll be weak as a kitten for quite some time, so best starting strategy would be to sneak around, trying to conserve ammo as much as possible. Get the items, get out. Prioritize getting more health and oxygem ASAP, then go with firepower. You don't NEED to always destroy every single turret and enemy, if you can just run past them and save ammo and time - do it. They don't even drop good loot until late game when you have the upgdrades.

3. Farm carefully on Level 1 Depth ships.
Get a few upgdardes and weapons going before attempting to go beyond Depth 1. There is no ticking clock and you can take as much time as you need getting the quest items.

4. Strafe around corners to get cheeky headshots on enemies.
This is a very core strategy that you must learn if you don't want to constantly lose all of your health. Enemy shots are hard to doge, and the best way to avoid damage is to kite them around corners or cover and then chip them one with a 1-2 combo pistol shot.

5. Try to lock rifts in cleared rooms.
This is a general tip, but if you see a rift, you try to close the room it is located in, lock the doors around it if possible. Another good idea would be to put a mine on it, if you don't want a Zec to spawn too soon while you're on a big ship.

6. Try to avoid ships with really bad conditions.
A lot of security elements and a shedload of Janitors? Nope! If the power on a ship is out and you have time, a good idea is to quickly run around and destroy all the key security elements before restoring power. Avoid fire at all costs, it will literally eat away your health, and if you're absolutely going for a ship with a lot of fire hazards, you'll amost certainly need to spend merits to get full protection from hazards as quickly as possible. Ships with no enemies but a lot of rifts are deceitfully dangerous! You'll have to rush as fast as you can before dozens of enemies start swarming you, don't waste a second on these ships! Conversely, fire and electric hazards also harm every enemy except Patients, so if you can get immunity to hazards on a ship, and then camp around a corner that's covered in fire, you can safely avoid wasting ammo.

7. Don't waste merits early game.
Save them for when you really need to get an advantage in a bad situation, you'll get all the items as you slowly farm each ship, but I would reccomend going to ships with a lot of merits and then stocking up on pistol ammo in the ships if you're running low.

8. Know enemy weakness.
I'll give you a few examples of how to counter tough enemies:

Spooks
- Toxin is their weakness. Shoot and forget. Alternatvely, zap them and 2 pistol headshots will kill them, don't be agressive with them, as they can be deadly when combined with other alerted enemies, so always bring a toxin gun if you expect a lot of Spooks.

Patients
- Rad gun is their kryptonite, can't be poisoned but radiation drops them like flies, they're more annoying than dangerous, but still can be difficult to deal with otherwise. Rivet gun is also a good option if you don't have a lot of rad ammo, but that weapon is kinda weak in other areas, so I wouldn't reccomend it. Grenades can also work, but aiming them is tricky and most of the time you'll just have to throw a grenade under your feet and run away since it's the most reliable way to not overshoot it.

Screws
- Avoid a confrotnation with them. Waste of bullets and way too much hp on high Dept levels. Either lock them in a room, shoot them with the mindwash gun, but the best option would be to use the teleport gun and shoot them in a locked room when you get that weapon

Zecs
-Rad gun hurts them even through the shield, otherwise throw grenades behind their shields or use rocket launger. Teleport gun also is best used on them as well.

Secbot
-If you alerted the cameras and you know secbot is coming and you can't rush to deactivate the alarms, you'll have to deal with him somehow. Teleport gun, obviously. Alternatively drop a lot of mines in a doorway you know he'll be coming through (you can tell by the sound effects displayed over them) or use a reflective shield, otherwise dont try to fight it without stunning since it can mow you down in 5 seconds with 2k hp. However, if you can spare the ammo, you could always just blow him up if you find him, but generally it's not a good idea since he can heal unless you deal a lot of damage fast. Rocket launcher or mines.

I'll share some of opinions on the best weapons and which ones compliment each other, and their overlall pros and cons.

Pistol
Basically your main weapon for the first hour hour of the game. Reliable against Juves, Janitors, exploding Tourists if you can't bait them, destroying cameras, destroying stunned sentries. Not so good against Scribes or Patients. Can kill all others in 2 head shots pretty much

Stapler
The second direct weapon you'll be using once you run out of ammo for the pistol. It's a shotgun that does a lot of damage really quick. Honestly, it has a nice range and functions almost indentical to the pistol, if you upgrade it, the only difference is that it's basically better, and you will definitely be using it in a combination with a zapper to kill stunned spooks or sentries. Still not powerful enough to take on Screws though.

Mine
I'd argue the best explosive weapon in the game, as it allows you to leave traps while stealthing, as well as take out sentries, sneak kill patiens, also good for just throwing around blindly, and it has a pretty generous range, but you'll be running out of them pretty fast, so don't be greedy. Works great against Patients. Pretty much good against everything. You could always drop 4 of these in a doorway that has a triggered Secbot coming up and it will usually be enough to drop him, sitll not good enough against a Screw though. Could be used against a Zec, but most of the time they will just block it.

Zapper
Basically, always grab one of those if you have enough ammo or if there aren't any zecs around, as it's incredibly useful for stunning cameras when your pistol cannot 1 shot them, because most of the time if you cannot 1 shot a camera, they will raise the alarm almost instantly, so it's actually a better idea to use a zapper for that. Has a nice stun duration on the sentries, so you can 1-2 zap and blam them! Is not accurate at all, so it's advised not to use it from a mid-range, but you can still land a shot after 2-3 zaps because the hitboxes are not super precise. Good for stunning Screws to be locked in a room, and generally works well against any enemy in your way, with the notable exception being Patients and Zecs.

Toxic dart
Very handy mid-game weapon that is best used for stealth missions against Scribes and Spooks. Because they tend to run away and generally can be a pain in the ass to deal directly, this is the weapon that you just fire-and-forget while sneaking around. 1 hit even unupgraded can kill most enemies, but just takes time, so it's perfect for more open areas in the ship. You can fire multiple shots to stack up the effect, but doesn't work on Patients and robots, so ultimately it's not top-tier weapon

Rad dart
Basically the same weapon as the Toxic dart, but way better. This is the weapon you always should bring to a ship full of Zecs and Patients. Shoot the area of the ship that you want to trap with radiation cloud, and any enemy that walks through will suffer dots that can spread to other enemies. Works like a charm in tight areas, with packed enemy presence, can even spread to machines, but is not super effective against those, is still good for silently taking down cameras though! Shoot the enemy directly and it will not leave a cloud behind. Can fire through Zec shields, and still be stealthy. Just try to avoid getting irradiated yourself, but even then it wouldn't do that much damage. You should always be on the lookout for this weapon parts and ammo.

Grenade
Basicallly the same as the mine but worse. Hard to aim because it often overshoots, doesn't do that much damage to the sentries and enemies. Only use it only if you have to deal with Zecs or Patients and you don't have mine or rad dart. It can still kill them in 1 hit, but most of the time you'll just be overthrowing it, or just throwing it at your feet and running away from the enemy, because that's a only reliable way to bait the enemy into it. One of the worst weapons in my opinion.

Bubble-shield
It's not bad, but it's not good either. Can be used against sentries and secbots, but takes a while, and eats up a lot of ammo. Most enemies don't deal enough damage to get killed in 1 swoop, but can be used to block tourist blasts, I guess. Honestly, it's just a weapon that you use when you have a rad dart and you want to save ammo on the zapper, so you just wait in a corner blocking while everything around you dies.

Portal rifter
The best weapon in the game hands down. Honestly, it shouldn't even be in the game because it's that good. It instantly sucks up any enemy/sentry that you have to shoot out before sucking up the next target. I call it the "Go to your Room!" gun, because you send everybody to their room. You see a Zec, or a Screw, or a Sentry, or any other annoying enemy, and you shoot them in a locked room that you've already cleaned up and then forget about their existence. Alternatively, you can also shoot them on an electric hazard or fire, if any are a present, which would kill most of enemies, even sentries, except for the Screw, the elite version of the Screw can walk out of the fire once, but wouldn't survive a second dip. Also, can be used in those military ships with dehydration machines to place enemies to the dehydration pads and turn their bodies into bio materials. Has only one flaw - doesn't work against cameras. Also, don't not really effective in a crowded room of enemies, so be mindful of your environment, because it still requires thinking.

Rocket launcher
Basically, the second best weapon in the game. You point it at a thing, and it dies. Sometimes it takes a couple of shots, and then it dies. Works against everything. In order to kill zecs, just aim slightly behind them.

Hypno-gun
Takes a long while before you can use this gun, and honestly, while it is pretty good, the ammo is hard to come by, and doesn't work on machines, so you'll only use it once or twice on a ship with a lot of Screws and Zecs.

Clustergrenade
Kittybomb
I grouped these two together because they essentially function the same. Throw them in a locked room and enemies go boom. Kitty can distract enemies, but not reliable, since they run in random direction and you'll just get shot most of the time in the process. Cluster just takes too long to explode.

Okay, this is basically the most important part.
If you think you're about to die, or are dying, or a gene nebula changed one of your core quirks, or gave you a bad one, or if you're unhappy with how the mission is going - then just quit to main menu and you'll start right before the mission. They recently patched it, as before you would die if you tried to quit while on a ship, so now you can freely abuse this stystem at every opportunity!