Beginner Guide

Where do I start?
For a first game, the Old Soldier is recommended.

First you may want to explore all the locations on the map, particularly the Western Passage (where you start), the Soury Village, and the Fair. Especially the Soury Village has many hidden locations that can sometimes give you some useful items. Make sure to talk to all the NPCs with a "T" icon on their tile and familiarize yourself with the early-game possibilities.

However, once you have familiarized yourself with these areas it is suggested not to spend too much time on them in the early game. The very first dungeon you're supposed to go to, the Smothering Caves, has a tough unique monster on the very first floor and the possibility of dying to it is realistic. As a result, you will be doing the same thing over and over again at the beginning of the game, which may make dying really tedious as most of the quest and secret content in the early game is not very random.

Passage to the Smothering Caves
Once you have collected the items you think you need, travel to the passage to the Smothering Caves and enter them. Here you will encounter a giant spider. He creates webs and attacks you with poison.

The tactic to defeat him is to realize that you can be faster than him. Turn on 'Tactic: Swift' and turn off 'Accurate Attacks' if you have it turned on. Hit him and move to a different tile. He will still attack your old tile and miss, as indicated by the color of the sword icon used to indicate an attack. As long as you do not get stuck in the webs you can use these hit & run tactics until the spider dies.

Alternatively you can lure the spider to the stairs. He will not follow you up. Use your meditations when in the safe area, and use the water barrel to heal and the kvas barrel to cure poison. You can keep doing this until he is dead, by hitting once and retreating upstairs. There is only one catch: some minor enemy types that roam this level can teleport you. In the worst case scenario you will find the entire area around the stairs to be covered in webs, at which point you have to use a different tactic to defeat the spider.

Once the spider is dead, the first floor becomes trivial. Only weak normal enemies will keep respawning. You can grind this floor to get a few levels, some meat, hearts, and most importantly potions. Consecutive levels will similarly spawn a unique enemy, except it is semi-random (each dungeon draws from a separate pool of enemies, but on what floor you will encounter them is random). Each unique enemy requires a different strategy, but some can be brute-forced by quaffing attack, speed, and protection beverages while hammering away and chugging healing potions.

From this point on you will continue exploring the Smothering Caves, where you will find connections to several other dungeons and even villages/temples.

Barrels
There are three different types of barrels. Don't underestimate the use of barrels, especially in the early game. They can be very useful in preserving their portable equivalents, such as antidote potions, healing potions, and food.
 * Water heals you up to half your maximum health.
 * Kvas cures status afflictions, such as Poison Attack, and gives you an attack speed buff.
 * Moonshine deals damage, but provides an attack power buff.

Talking
Talk to every NPC you come across with a "T" on its tile. This means they have something useful to say. Often you will encounter merchants and quest givers this way.

Equipment and Tactics
Don't forget to equip the items you start out with and set the tactics you feel most comfortable with (although you will likely change tactics for specific enemies). Always make sure you are not attacking with "Power Attacks" if you want to keep your weapon from breaking. It is easy to accidentally hit the '6' hotkey without noticing, as this attack type gives you no warning.

The 'Accurate Attacks' type is not as useful as it sounds. It will add 6 ticks to your attacks, which means that attacks take a lot longer to execute. This gives your opponents more time to react. Only use this against enemies you have a hard time hitting in the first place.

Gaining Levels
Be very careful when leveling. The main character, the Old Soldier, cannot upgrade his health when leveling. However, you can still spend points on it but it will have no effect. You'll just be wasting points! Furthermore, each character seems to have a cap placed on their attributes. After 3 or 4 upgrades of your Attack Power on the Old Soldier you will reach this cap. Just like with HP, you can keep upgrading this stat but it will have no effect.

Every 5 levels you will be able to upgrade a talent. What type of talents you can upgrade depends on the character.

Experience
As of yet, the exact mechanic is not fully explored.

Experience (XP) is gained by defeating enemies. In their tooltips you can see how much experience they provide. In order to gain a level, XP must pass a specific number that increases as you gain levels. XP is not spent when you level up, allowing you to use it for other purposes (such as enchanting your armor). However, every point of XP spent is a point you need to regain in order to reach the next level.

XP gain is (likely) determined as a combination of your current level and the number of times you have defeated a particular opponent. Normal enemies quickly only give you 0 experience, therefore it is recommended to be very careful when spending XP as it is not easy to regain.

XP can be spent in the following ways:
 * Spend it at a shrine (e.g., there is one in the bottom part of the Western Passage) to upgrade your equipped armor with resistances. This can quickly get you 100 in some resistances, making some attack types completely powerless.
 * Use the Master Tactic. This costs 10 XP per hit, but you cannot miss. Only the Old Soldier and the Lich can use this attack. Use it sparingly, but spending some XP is better than dying so don't forget about this ability when facing a tough unique opponent.
 * Be absolved of all sins at the secret altar in the Subterranean Dwarves village after doing what the dwarf Posh asks you to do. This also works if you have no experience.
 * Spend it on the Imp, at the entrance to the Smothering Caves. He will fully heal you for some XP. This is not recommended, however. This also works if you have no experience.

Inventory Management
Inventory space is limited by number of slots, and through stacking limits. For instance, you can carry only 5 of each potion, regardless of having any free slots. By storing items in your portable chest you can avoid the stack limit, but your items are not easily accessible during combat. Furthermore, the portable chest has a stack limit of 1, and only a limited number of slots (add how many).

It is  highly  recommended to drop excess items somewhere easy to reach (e.g., at the Western Passage) for multiple reasons:
 * Corrosion affects all the weapons (or armor and shields, and possibly rings) in your inventory regardless of whether they are equipped or not. Corrosion does not destroy your gear, but it weakens it tremendously and can remove magical effects (as from a potion). Enemies with "weapon corrosion" will only corrode your weapon. Acid attacks (and acid pools) can corrode all the gear in your inventory. Items stashed in your Items stashed in your Portable Chest will not be affected by corrosion. For 1 copper you can repair all corroded weapons (at the Fair) back to their original values.
 * Items can be stolen by the rare imp monster. He might even steal your portable chest. They can be retrieved by searching the dungeon floor, but the little bugger will keep stealing your stuff until you kill him.
 * When resurrected (e.g., through a resurrection pebble) you will respawn in the Western Passage without any of your items. Having no back-up gear makes resurrection almost pointless.
 * Rats rummaging throughout the dungeon floor cannot be attacked, but if they walk on top of any items lying on the floor, they will destroy them. Therefore, don't use dungeon floors as a storage place.
 * Talking about storage places, you can basically use any non-dungeon location to store your gear. It's best to do so in easily accessible locations, such as the Western Passage.

Consumables
Potions and food are the primary consumables in the game. Each of these has a stack limit of 5 in your inventory, and you cannot carry any more unless you put them in your portable chest. The most commonly dropped potions (in the early game) are attack, speed, and protection beverages, as well as universal antidotes and healing potions. Certain enemy types seem to drop only specific potions (e.g., kobolds only seem to drop antidotes).You can furthermore grind common enemies for these potions as these enemies keep respawning on a dungeon floor. Therefore, feel free to liberally use these potions when attacking unique enemies.

Enemies may drop two forms of meat: Raw Meat, and Hearts. Hearts should be eaten straight away, as they provide a chance to increase your inherent resistances to certain types of damage (e.g., poison, frost, fire, evil, confusion, and so on) which is immensely useful. Both Raw Meat and Hearts can be cooked when adjacent to a fire and pressing the 'r' hotkey (which will automatically cook and drop all the meat in your inventory). Raw Meat restores only a tiny amount of health, but cooked meat restores a lot more.

If you do not cook raw meat, it will spoil quite fast and be removed from your inventory. Do not hesitate to retreat from the dungeon in order to cook your meat and return. It is the primary form of healing, after all.

Arrows are also a type of consumable, since the arrow is destroyed upon use. You can learn to craft arrows (requiring 1 steel ingot) by bringing Utt (in the Temple of Silence) the Glass Sword that Arrakar gives you at the Soury Village, or just buy them from Arrakar. Furthermore, arrows drop from unique enemies.

Status Afflictions
Afflictions can target yourself, or your equipment. There are several forms of afflictions:
 * Poison Attack: Deals damage over time based on your poison resistance
 * Frost Attack: Deals damage over time based on your frost resistance
 * Fire Attack: Deals damage over time based on your fire resistance
 * Acid Attack: Deals damage over time and afflicts corrosion on all the gear in your inventory
 * Fate Attack: Deals damage over time based on your evil (?) resistance, and seems to resurrect you upon death (not entirely sure if this is the source)
 * Confusion: Makes you move in a random pattern
 * Corrupted: Provides a quite substantial debuff (that seems to get worse over time)

Items can be subjected to certain afflictions as well:
 * Corroding items will receive damage and can break (or lose attributes, not sure yet) over time. Getting rid of the source of corrosion (such as the Acid Attack affliction on yourself) will stop your gear from corroding.
 * Cursed items cannot be unequipped once equipped, but have no other negative effects. There are several ways to unequip them regardless. You can spend 7 copper for a prayer from the monk at the Fair, which removes the curse without destroying the item. Next, you can drop all the gear you don't want to lose on the floor and create an acid pool by using an acid potion. Step in the pool and watch the corrosion effect destroy the item. Lastly, if the cursed item is a weapon, you can use "Power Attacks" to break it by hitting enemies.
 * Corrupted items will give you a corruption when equipped. Corruptions are bad and become worse over time, as they can (seemingly permanently) reduce your stats the longer you are corrupted. It can be removed by using a special potion (add name here) that uncommonly drops from unique enemies, or by spending 7 copper for a prayer from the monk at the Fair.

Grinding
It is possible to grind for XP and items, particularly in the early game. Once you dispatch the unique monster roaming the level, only normal monsters will keep spawning. They become trivial very quickly, especially because they don't respawn in large numbers. This allows you to grind for XP until you reach the cap (XP gain comes with diminishing returns, and at some point certain enemies will not give you any XP), and most importantly grind for raw meat, hearts, and potions.

If you are having trouble in subsequent floors, you can easily reach around level 6 or 7 on just the first floor of the Smothering Caves.