I'd like to start a thread here of player tips,..not spoilers to help those who don't know exactly what to do or what they are getting into when they purchase Gothic 2. Please feel free to add to this if you have any tips for new players because this is no Wow,..this is an extremely hard game and anything I discovered was found by trial and error because there didn't seem to be a thread to help.
- Make sure you get yourself at least 5 mana early in the game as you will need scrolls to win some of the more difficult fights.
- Never take a fight for granted because you will die if you do.
- Scrolls are used by assighning them a number(they do have a default number assigned) Once you see energy in your char's hand,..it's ready to be cast,..tap forward and left click to cast after highlighting an enemy name.
-Archery is the same if you pursue Dex,...equip the bow (assigned number or default),...and tap forward while holding the left mouse button to fire. You need a lot of dex and a good bow before you start making good strikes on the enemy.
-You'll often find most enemies too tough for you,...don't worry,..somewhere is a beatable monster,...exploration is key. You'll find out where you're not supposed to be fast. Trust me.
-Explore every nook and cranny,...iv'e foun many a dead warrior or skeloton loaded with scrolls and potions,..weapons, and gold off the beaten path.
- If you find a battle that is way too difficult(eg/spoiler) Like the bandits on the bridge by the tavern. Be creative. What I did was get they're attention and lead them too the tavern where all the people in the tavern drew weapons and began slaughtering them. You lose expierience but afterward you can go up and get their loot.
- Stay away from ogres and skeletons until high level,..you'll be dead before you know it.
So basically this a game that takes a ton of patience and exploration to reap the rewards. Every battle won is exhilirating though unlike an easier game. I'm so happy I got this game because it has given me new respect for rpg's,..and this is a true one.
Feel free to add to this because it will probably help some people who get frustrated early to keep on playing and find out how much better this is then most rpg's.
Lockpicking- Great skill to have as it will net you healing pots,..weapons, and other things.
General Rule- Save before each locked chest. It's very simple,..each lock has a series of left and right commands so keep a pen and paper handy and wait three seconds before each push or you will go too fast and break the pick. Each chest has a series,..easy chests maybe have 4-6 pushes harder ones more. So Left Click to begin when you face the chest. Now start with left or right arrow if it says "That sounded good" wait three secs and try Left or right again,...keep this up writing l or r for each one correct and if you get one wrong,...load the save before,..don't worry , the combination doesn't change. Once you get it right the chest will open.

Very, very usefull tips for everybody. I took me a lot of reaserch to put this together:
ALCHEMY:
You can obtain a total of:
11 dragon roots + 1 in act 6, on the ship
17 goblin berries
21 king's sorrels + 3 in act 6, on the ship
You can obtain:
ACT 2:
1 str potion from Zuris (buy)
1 str potion from the ship (you can sneak onto the ship)
1 dex potion in a chest in the sewers near thieves guild (quest related)
1 dex potion in a Field Raider cave
1 dex potion on a shelf above bandits camp near Sagitta's cave (you have to jump on the tent and then on the shelf
1 str potion in shadowbeast skeleton's cave in Valley of Mines
1 dex or str potion as a quest reward from Oric in Valley of Mines
1 king's sorrel can be bought from Sagitta
1 dex potion near dragon snappers pack (not confirmed)
ACT 3:
Constantino sells 1 goblin berries and 1 sorrel
Salandrill sells 1 dex potion
Zuris sells 1 dex potion (not confirmed)
Sagitta sells 1 dragon root
ACT 4:
Constantino sells 1 goblin berries and 1 sorrel
Sagitta sells 1 sorrel
ACT 5:
Constantino sells 1 dragon root and 2 sorrels
Lutero sells 1 sorrel
Sagitta sells 1 sorrel
ACT 6 SHIP:
You can buy a total of:
1 dragon root
3 king's sorrels
To be continued...

Also note that in vanilla Gothic II Orc Elites occasionally have Dragonroots and Black Goblins occasionally have Goblin Berries. The drop rates for these are extremely rare, however, and from what I've read this feature was removed in Night of the Raven (the GOG installer installs Night of the Raven by default unless you specifically deselect it).

That feature was removed. In my opinion vanilla G2 was unbalanced.

Here's a couple of tips about melee combat:
First and foremost, do NOT button mash: whether you are comboing an enemy with the LMB or using the Left/Right swings, timing is extremely important, or you character will get stuck in mid-animation and the enemy will have an opening to combo you back. Your skill level will effect the number of moves your character can perform and the timing required to combo them effectively. You can easily practice by trying swinging you weapon in an empty area (so as not to anger other NPCs)
Second, you CAN mash the parry button: unlike in Gothic 1 where pressing the parry button will put the character on the defensive for a certain amount of time, in G2 the parry is pretty quick, but it allows you to mash the button to keep your parry up. While experienced players will avoid this, it can be useful to a beginner. Just keep in mind that 1) it only works on a single opponent, 2) it doesn't work on animals and monsters and 3) the enemy can still hit you if it attacks at the right moment.
Third, backstepping is one of the most useful combat moves EVER: have you noticed that sometimes when you attack an animal, it backsteps your attack misses? You can do the same too! With a weapon drawn, pressing the Move Backwards key will make you character backstep: if done correctly, you will not get hit. One of the basic melee strategy when figthing monster is to let the enemy rush at you, backstep out of his attack, hit him a couple of time with a combo and then repeat. This technique can also work against multiple opponents, as long as they are in front of you. HOWEVER backsteppind does NOT work against ranged attacks and spells.
Fourth: when engaging an archer try to close as quickly as possible while zig-zagging so that you can reduce the chances of him hitting. Zig-zagging works also against most spellcasters.
Fifth, if engaging a spellcaster, keep pressing the attack! If you are fast and keep close enough, the enemy magician will be unable to cast his spell at you.
Sixth, try to fight one-on-one: all the tips above works well when fighting a single opponents, but if there are more, expect to get surrounded and killed.
Seventh, enemy archers and spellcaster can be your friends: if you are engaging a group of enemies, some of whom have long ranged attacks, you can maneouvre so that they will hit the melee fighters instead of you. Friendly fire exists and you can use it to your advantage.
Eight: enemy lock is your friend. Just bind it to a key that you can easily reach so that you can toggle it off if you have to retreat
Ninth: don't bite more than you can chew. In Gothic YOU WILL find creatures that can easily kill you, even at the start. Just keep your distance and avoid them until you have become more powerful and experienced.
Just remember that these tips are for beginners, and as such are general and relatively limited in scope, so use your brain and think before you attack something: you might even find that some of the most fearsome monsters aren't so though as you tought them to be (trolls ;-) ).

Here are another couple of Gothic 2 tips for new players:
While visiting the market district in Khorinis there are a couple of things you can do:
-Talk to Daron, the Fire Mage standin near the eastern gate and he will try to convince you to donate some gold to the Church of Innos; while expensive, there are some benefits in doing so: for every 50gp you donate after the first donation, Daron will bless you with experience points and permanent stat boosts. Just remember that he will be there for the entire game and as such do not spend all your hard-earned gold as soon as you meet him. Also, give him no more than 50gp at a time.
-Talk to Abuyin, the guy standing on the other side of the free beer table, next to the water pipes near the Inn, to recieve a quest and you can also pay him to give you a prophecy: said prophecy will gain you some experience points, give you some clue and the cost depends on the current game Chapter; as such, it will get more expensive the farther you are in the main storyline
Magic spells for the newbie adventurer
In Night of the Raven scrolls are VERY useful, since the mana cost is fixed (unlike regular Gothic 2), but even then there are some spells that are not really worth buying. As such here are a couple of spells that a new player might want to buy:
-Ice Block: THIS is probably one of the most useful spells you can use, and thanks to scrolls you do not need to be a mage to use it, even if you don't increase your mana reserves. It fires an ice projectile that if it hits (pretty much always, unless the enemy is EXTREMELY close), it freezes the target for a good 20 seconds, usually enough for you to rush at him and kill it or as a crowd-control spell.
-Destroy Undead: as the name states it kills all forms of undead in one hit. Very useful in some areas where you have to face skeletons.
-Oblivion (scroll only): can be used if you have been caught stealing in someone's house, as long as you cast it after you knocked the guy unconscious and there are no witnesses nearby; the target will lose all memory of the event and you will be able to talk to him normally (and won't have to pay the fine in Khorinis)
Transform into X (scrolls only): a few of the animals you can transform into can increase your land speed and you will not get attacked by other monsters (except for sheeps and, I think, giant rat), however fellow humans WILL attack you on sight (or run away if you have turned into one of the most powerful beasts). Press the Enter key to end the transformation
-Light: this spell creates a small glowing orb that follows you around and light the area near you. While using a torch is cheaper, you can stay in combat mode without having to douse the magical light. While playing you can also find a Paladin rune with this spell on it; don't bother: if you are a mage you have the "standard" light spell (the runic version costs you a whooping 1MP to cast), wich is superior in all respects; as a paladin you are still better off using scrolls or torches (it is THAT bad of a spell).

True, but I considered that as a spoiler / bug / some Easter Egg and did not use it. Don't, it makes the game much too easy (IMO).
Great spell. Buy the scroll whenever you find one. Also buy any "summon demon" spell. Demons can solo almost every boss (except maybe the last one) who are otherwise violently hard.
Important tip :
- Collect and eat the Apples you find. Every 10 apples eaten, you get a permanent +1 in Force.
- Same with mushrooms (every 20 of them) and mana.

Skeletons are great for trolls. Undead seems to have NO AFFECT on the undead dragon boss (in NotR). Another excellent scroll (but not in Gothic 1 is firestorm and ice wave whenever greatly outnumbered. Lightning kills skeletons with one hit. Save the kill undead (quite limited number) for the skeleton lords. Orcs generally run from shadow beasts.

Just want to thank you all for the tips -- they really do help! I just stumbled onto this game (the reviews caught me ) and am really liking it :)

Thanks for the advice!

Well, I recommend everyone do most or every quests at the city, and before you arrive at the city, try to follow the path. The thing is, if you try to join the Mercenaries or the Fire Mages, it's really hard to go there as a low level, so you should do the city life and build yourself there (Trainers aplenty) before going to meet the Mages or the Mercenaries. I suggest a minimum of level 5 before venturing outside.

Also, before arriving at the town, you should do the farm quests to earn experience. If you want to enter the city without paying a dime or without doing any work (Like picking the 10 herbs) you can just jump the wall.

On combat, you should always try to fight 1 enemy at the time unless you are confident that you can defeat more... More than 3 enemies is deathwish

There used to be an awesome guide at GameFAQs from the time of the original G2 release (2005) which is a must. Avoid the walkthrough if you don't want spoilers but the Combat section (how to chain your combo attacks and how to distribute your hard earned Learning Points) is priceless!

http://www.gamefaqs.com/pc/561413-gothic-ii/faqs/28891

You probably mean this one :)

Actually, I used this other one =)

http://www.gamefaqs.com/pc/561413-gothic-ii/faqs/24278