Unlike Witcher 2, rolling around is no longer the basis for most your combat maneuvers. Not only are you no longer invulnerable during rolls (unless you take a specific skill), but rolls use up precious stamina. You want to sidestep to dodge most attacks, only rolling away when a large monster charges / an AOE attack is heading your way.

On the other hand, just *like* the Witcher 2, you generally don’t want to be fighting a bunch of guys at the same time. You do a lot more damage when hitting someone from behind, and enemies do a lot more damage when they hit you from behind. Maneuver, use signs, bombs, and sidestep to separate enemies from the pack and take them down.

If you keep button mashing, most enemies will eventually parry your attacks and counter-attack to great effect. The general rhythm of combat is something like: 2-3 sword strikes, sidestep / riposte enemy attack, another 2-3 strikes, use a sign / bomb / roll as needed, attack at the most vulnerable target.

You want to sidestep around monsters and animals, as their counter-attack windows are minute to nonexistent. Learn to riposte human enemies and a number of humanoid monsters (drowners, wraiths etc).

Various damage effects - bleeding, poison, burning - are better than they seem. Not only do they scale with enemy health, retaining their usefulness even at high levels, they also take effect even when the enemy blocks. Nothing like taking a few swings / whirling through a group of a dozen bandits and having them all keel over after a few seconds as the effects take place.

Read the bestiary entries for new enemies – they will often tell you exactly how to defeat them. You get bestiary entries after killing an enemy for the first time and / or by reading books dealing with particular creatures.

General sign usage: Quen for when you’re having a hard time avoiding enemy attacks / when they’re going to do a lot of damage if you make a mistake. Aard when you’re fighting humanoids near your own level, as you get a one-hit kill prompt if they get knocked down. Yrden for fast enemies that keep dodging you / wraiths (specifically, you won’t be able to do a lot to Noon/Nightwraiths without Yrden in place). Axii for when you’re fighting a single annoying enemy (it can be surprisingly effective at stunlocking enemies far higher level than you). Igni is a great general purpose and crowd-control sign – it can disable enemies that catch on fire, it allows you to do damage when you’re afraid to close in, and it damages groups just as well as a bomb would.

Regular and alternate sign usage explained in detail here:
https://www.youtube.com/watch?v=2jQcuiXpjcA

Bombs - what are they good for? Detailed explanation:
http://www.accelerated-ideas.com/news/witcher-3--which-bombs-are-the-best.aspx

Since your potions / bombs / blade oils get automatically refilled as you meditate, never be shy about using them constantly. Experiment with different decoctions / throw bombs around willy nilly / never go anywhere without Hangman’s Venom on your steel sword and some potions in your system.

Geralt sometimes growls something along the lines of "the weather is doing a thing". Certain potions have special effects if imbibed during specific weather conditions, and Geralt is letting you know that this might be a good time to use them.

Andrenaline points - what do they do? An oddly common question with a simple explanation - as you gain APs, your sword strikes do more damage. You gain them by doing damage in a fight and lose them over time / when you take damage. Various perks allow you to gain APs in different ways and/or use them for different purposes.

You generally don't need to manually aim your crossbow. As long you're locked onto an enemy (that is, if an enemy's name + healthbar are showing) you will automatically aim at it just by hitting the "use equipped item" key. Crossbows are useful underwater, for downing flying enemies (Aard is more dependable though) and for drawing aggro.

Horse combat - you'll sometimes miss swings that really look like they should have hit, particularly if you try to do "ride-by" blows. Aiming Roach directly at the enemy, and swinging as his nose connects is actually a lot more certain.

Enemies far higher level than you - marked by red skulls - aren't really worth fighting. Even if you manage to defeat them, the reward is either going to be something you can't use at your level, or scaled to your level and thus worse than it would be if you got it a few levels later.

You’ll have the opportunity to buy character reset potions fairly early in the game, so don’t worry about messing up your character build. Still, here are some things you may want to know.

You get 12 “active” skill slots into which you need to insert skills in order to be able to use them. These open as you level up, at a much slower rate than you’ll get skill points (particularly if you’re exploring the map and using Places of Power). Ergo, you should focus on leveling a small number of skills you’re currently using, rather than opening a large number of skills you won’t have enough slots for.

You can apply 1 mutagen for each three active skill slots to receive an additional bonus. For instance, if you apply a Greater Red Mutagen to three slots that have a single Red skill equipped, you’ll get a 20% attack bonus. 2 red skills will equal 28%, and 3 a 40% increase (or roughly that – the point is that if all the active skills in the slots to which the mutagen is applied are of the same color as the mutagen, the bonus is greater).

Since general skills don’t have a corresponding mutagen, and can’t have more than 1 skill point invested in them for greater effect, you generally want to avoid investing in them (unless you’re running a “general perks always active” mod). The two exceptions are Gourmet, which makes food act as a slow and long lasting regeneration potion (invaluable on higher difficulties, particularly when you’re low level) and “Cat/Griffin/Bear” school, which gives you fairly significant bonuses when you wear light/medium/heavy armor.

Though I noted that you’re free to experiment with skill combinations and that most are viable, some skills are traps not worth investing in: The crossbow should remain a utility weapon, and attempts to make it a primary damage dealer are basically wasted skill points. Crippling Blows does a *set* amount of damage (unlike the general bleeding critical effect, which does a portion of the enemy vitality) and thus scales incredibly poorly at high levels (particularly annoying for a high-level ability).

The ability to have more than one sword oil applied at a time is basically worthless. The game practically never mixes enemy types (well... Wild Hunt warriors and their hounds, but that's also extremely rare)

Arguably, the Axii upgrade makes the basic tactic of stun-locking dangerous enemies impossible, and is too slow and ineffective to be worthwhile – enemies are actually fairly bad at fighting other enemies, and it will generally fail against high level foes (exactly the kind of enemies you *want* to make fight each other).

Acquired Tolerance (in the Alchemy tree) is fantastic in pretty much any build - you always want to be able to drink more potions. Also, pretty much every alchemy recipe (potions, oils, decoctions) counts, so your tolerance grows far more quickly than you might assume.

Most new potions / oils / decoctions you create will use White Gull as an ingredient. Stock up on the basic components – Arenaria, Mandrake Cordial, Cherry Cordial and Redanian Herbal – whenever you get the chance.

Good sources for new alchemy recipes – Keira Metz and the Pellar in Valen (both found during the Bloody Baron quest), the halfing Herbalist north of Oxenfurt, the halfing Herbalist in Novigrad, Gremist in Skellige.

Skellige Drowned Dead have a fairly good chance of dropping Red mutagens.

Check monster lairs carefully – there’s a fair chance of finding at least one random diagram / recipe hidden in each. If the map icon for the lair is “monster lair” or some other unique name rather than the generic “entrance”, the icon will stay white as long as there’s loot to be found within the lair, and turn grey once you’ve found everything.

Blacksmiths and Armorers will often have treasure maps with the locations of diagrams that will allow you to forge Witcher school weapons and armor. These are generally the best weapons / armor for their level, can be upgraded repeatedly to be the best weapons / armor for higher levels, and are well worth finding / forging.

Most high level crafting diagrams will involve one or more of: Dimeritium Ingots, Meteorite Silver Ingots and Cured Draconid Leather. Don't sell stuff you can craft or dismantle into any of the above (or their components).

Check to see what dismantling your items will get you. Some stuff that sells for nothing will dismantle into valuable components (for instance, clams and seashells).

(Just the first few, as I assume you'll be able to figure out the later ones)

Devil by the well - lure her into a Yrden trap and hit her there. Crossbow or bomb her copies, as they drain your health when they get near, healing her.

Griffin - use the crossbow or Aard to knock it out of the sky. Try to get behind it for a few free hits before moving away / Aarding it again. Quen up, because a single strike can do a lot of damage. Allow Vesemir to act as a distraction.

Nithral - you face this boss after following up on Keira Metz's suggestion to visit the mysterious elf. This results in a lengthy dungeon crawl, so make sure you have some potions / food saved up for the boss.

He hits hard, so have Quen up and don't get greedy - have Keira act as a distraction, take a few shots at him and back away. He will shield himself and summon Wild Hunt Hounds when you damage him enough, and will do so three times over. You could try to defeat the hounds quickly to stop him from regenerating all his health (you can stand in the middle of a portal and hit them as they come out) but that's not necessary - just don't take too many risks and be aware that he doesn't keep his healing cycle forever.

Werewolf - This is going to sound sort of cheap but... level up to 7-9 before you fight him. Having enough of a damage output to deal with his HP in general and his regeneration in particular is largely a function of level rather than tactics. Igni stops regeneration, but no quite enough if you're really low level.

Mod merger: just there to make sure all the mods play well with each other.

Fast travel from anywhere: saves on quite a bit of annoying backtracking when exploring. Can mess up quests (when you're supposed to follow someone / when someone is supposed to talk to you the moment you exit a building) so use with care.

Map quest objectives: Shows you all current quest objectives on the map, instead of just the quest currently highlighted. Immensely useful, particularly when it comes to scavenger hunts.

Auto-apply oils: saves you a lot of hassle, since applying oils through the inventory system is just a time-wasting bother. Stops you from getting the Even Odds achievement.

Better torches: Climb, cast and fight without putting your torch away.

Cheap dyes everywhere: now you can be a shiny Witcher princess before the endgame starts.

Choose which Alcohol Refills Alchemy: Finally has Geralt use up all the Dwarven Spirits he's lugging around instead of throwing away a White Gull every time he meditates.

The mods above are basically just a matter of convenience. The mods below actively change how the game plays, so fair warning if you want a "purist" experience:

General perks always active: exactly what it says. Makes the general perks a lot more viable, since there are a lot of reasons not to use them in an umodded game.

Select all mutations: allows you to use more than one mutation at a time in B&W. Kinda gamebreaking, but IMO the mutations are hard enough to get that being forced to only use one is a bit lame.

Indestructible items - no more weapon / armor degradation.

Buyable Doppler and Succubus Mutagens: Satisfy your completionist urges AND your moral concerns at the same time.

You can save a decent amount of space by deleting all the different manuals and maps that come with the game by default. Right click on the game in your library, "properties - local files - browse".

You can't lose a contract or get paid less than the default bounty when haggling about the payment of a Witcher contract. The only reason not to haggle is if the compensation is too minor to bother about one way or another.

There's a certain assassination quest chain in Novigrad / Oxenfurt that seems to come to an abrupt end. You're meant to visit the Island of Mists before it resumes. (Once it does, make sure you never choose to push people aside. The results are unexpected and quest-failing)

Novigrad's "run around and talk to people" quests can be a bit overwhelming. Which is why Novigrad comes with a free trip (well, a trip that refunds its cost the moment it ends) to Skellige attached. Whenever you feel bored looking for your friends, go take a vacation in Viking-land.

Skellige quests - if you take up Lambert's quest before you first travel to Faroe island, you'll miss out on a minor quest there. Before you leave the main Skellige island to help Hjalmar / Cerys, make sure you visit all the towns on the island and complete the major quests. There's a fairly interesting quest chain you'll miss out on after Hjalmar and Cerys come back home.

Do you see all the "?" in the Skellige seas? Just vendor trash. Ignore unless you have hours to waste while listening to a podcast (leave it for the late game regardless, as the contents will be worth more when you're higher-level)

When you arrive in Kaer Morhen, you should help Lambert and Eskel before you help Yen.

Once the battle for Kaer Morhen starts, the game will quickly drop about 5 levels on you. You're probably almost the right level for Superior Witcher gear as the battle starts - have a full suit of gear in your inventory, because you won't be able to access your stash for a while.

As you start the Blood and Wine expansion, visit the Ducal Camerlengo, the invitation to a Gwent tournament (if you're into Gwent) and the Quarry before you start exploring the countryside. All three have signboard notices directing you to them, and you'll be lost and confused if you try to explore without getting directions from those three places.

Blood and Wine has two different ending paths. They're both fairly elaborate, but you can decide to find the Elder, then switch to the other path just before you actually travel to his home, to see most of the content AND get the "good" ending.

You can occasionally nudge Roach off of steep cliffs (press against the edge and keep hitting the jump button as you steer left and right) . If he doesn't despawn along the way, leaving you to splatter on the ground, it can make for a handy shortcut.

Like and favorite if you think the guide is helpful, let me know what I'm missing if you feel it was incomplete.