If you have played crawl you will have noticed that when you leave a floor it shows everyone's new level (as oppose to the last floor). While you level up, everyone else gets more vitae. This vitae is used in the next stage of the end of floor where you level up your monsters. You will get about 5 vitae per enemy level up (more vitae is awarded with less players). This is the only way to get vitae, so the game has a balancing system. As you upgrade your monsters, they will eventually reach a Max Evolution. Max evolutions cost from 40-50 vitae. Although it is great to have a fully evolved monster, make sure to be upgrading your other monsters because when you step on a pentagram, you get a random monster. Also, make sure to grab the statues. You can possess a statue like any trap pentagram, or slime. When a statue is in a room, the doors do not close (so you might want to leave if you are the hero) but when the statue is possessed, you cannot leave. Statues are the only way to play as The Taxman or Gaben. There can only be only statue per room so make sure you get it before your fellow ghosts! Also dealing damage as monsters (or traps) gets you blood. Make sure to land the last hit on the hero because this is the only thing that defines who the next hero will be.

Every floor has one. Each shop will have a sign outside of its door (does not say words, but is currently the only different door). Another way to get to the shop is by using 5 blood at a blood fountain blood. In the shop you can get a 1 for 1 blood to gold exchange rate by pressing "a" (normal attack) near the sacrifical idle. Gold can be used in the shop to buy swords, spells, potions, and trinkets. Another way to get gold is by attacking monsters with a theiving knife (a certain God starts with this, attack foes to make them drop their gold) or by opening chests (just attack it). The better a sword is, the more it costs (by this I mean if it is magic, then it costs extra gold, or if it has certain sword traits). The current object with no defintion in the shop is the Magical Ectoplasm. This trinket allows you to have a maximum of 4 slimes (as oppose to the normal/starting maxium of 3).

There are currently two bosses. The only way to win the game is to defeat a boss. Each boss has 3 controled segments. The bosses are Kourok and Ghildark. Ghosts can control the fallowing for Kourok: left arm (shoot bubbles with upon contact with the human will make him move slower, and unable to attack) head (will shoot giant slightly controlable laser but will open Kourok's mouth) and right arm (shoots red bubbles that upon contact with the floor will expand into damaging red acid). Ghildark's contols are as fallows: Left head (shoots fire, similar to dragon special. Can turn but can only point in the quadrent it was originally facing when fired. Can also set the human on fire) Middle head (Shoots a ball of ice. Upon contact with human it will do damage and add an ice affect {slows him down}) and the Right head (shoots balls of green acid similar to Kourok's left arm). The way to beat Kourok is to send a slug (they fall from the ceiling during this battle) into Kourok's mouth (attack the slug to send it across the screen)(You can also you laser beams, bows, ect to hurt Kourok any time during the battle)(Mouth will only open if the middle head is firing, or if the middle head has not fired in a short period of time). If his mouth is not open, it will deal a small amout of damage. If his mouth is open, the slug will fly inside and Kourok's brain will become exposed allowing you to hit it with your sword (Ghosts will not be allowed to attack at this time). The way to defeat Ghildark it to attack it (this can be done at any time unlike Kourok). When Ghildark reaches half health, a random one of its heads will be detached from its body and have free control from the body, at one fourth health, another head will be detached and at 0 health, the last. When a head is detached it gains its own independant health bar. If a head's health runs out, it will die. To kill Ghildark, you must kill all three of its heads. During the battle, a magic samuri will appear around the battlefeild to aid the human. He will drop three peices of health, and then 2 peices of health at the same time. To prevent him from doing this, Ghildark can shoot him with any head. This will scare him away for a short period of time. Defeat either boss to win the game. When the boss has been failed three times, the third person to try will lose the game. The ghost with the highest amount of XP will win the game. If you fail to defeat the boss the first two times, you will be teleported back to the portal room (it may be a good strategy to attempt the boss if you have less then two bars of health even if you know you cant win)(WARNING: With less players the boss will have more health and do more damage)

Some rooms sometimes have traps. Traps can be controled by ghosts, cannot move, and cannont die. If traps are in the room, and no slimes, monsters, or red crystals, the human can leave the room. Red crystals are only a part of trap rooms. They are stationary non moving obejects that must be broken to leave the room (they also drop small amounts of XP when broken). It is a good stategy to drop a slime in rooms with alot of traps if the hero is on low health to finish him off. There also have to be no more possesable pentagrams for a trap to become possesable. Gravestones can also spawn randomly. They are purely an only good for ghosts item. They cost one slime to use. To use them, hit the posses button above them as a ghost. They will power up your next monster. Food items are a good for hero only item. The pure benifit ones are red dots, potions, and ham (ham heals you the most, then potions, then red dots). touch any of these to heal you. More food items are cauldren, fountain, and meat. These are risky health options. They can be used when there are no monsters of slimes in a room. The effects are as follow, meat will heal you or make you sick (sickness will only affect you for the rest of the current life, it will make you occasionally stop and barf) fountains will either heal you or poisin you (poisin will affect you for a short time, by draining your life) and caudrins will either heal you or make you sick (like the meat). Last of all, floors will sometimes have alters, podiams, and wishing wells. These cost upfront money. They are for the hero. podiams and alters will help you for the next battle. It is a good plan to pay for one of these before taking on the boss. Wishing wells cost 5 gold and may give you gold or XP in return.

To fight the boss you must reach level 10. When you reach level 10 you can go to a portal room and teleport to a pre boss room (these heal you with lots of red dots).
The ways to level up are, wishing wells (dont give very much XP) breaking red crystals (Give little XP) and killing Monsters/The human. Besides being able to access the portal, leveling up will give you health and speed bonuses. After reaching level 10, every additional level will give you 25 blood.

Before you start the game, you will choose a god to praise. Picking one will choose what monsters you get and give you a special bonus (glub glub glub means nothing, he just starts with an evolved monster). There all currently 11 gods to choose from. There are also secret gods. these gods are hidden in the game and can only be unlocked by typing in a special name. These have no effect on the actual gameplay. Try using the name "HL3" "SPN" "TNE" or "MMM". There are lots of others, so lets see who can find them first.
1.5, now you can also taunt a God. Taunting a god has no benefits and is made to add extra challege to the game. There are 5 different gods to taunt. For example, taunting glub will make all your monsters glub. Also you cannot evolve them. Ever. As the human, you will be very slow, you weapon will always be club which cannot be changed, and your spell will always be putrid spit. GLUB GLUB GLUB. Also, beating the game when taunting a god, will show you taunting the god. For instances of this, go down to the sucessful taunt section.

hooray, update 0.4. In the update news, it says there is a small chance of rare rooms spawning. There is the tresure room (left, has lots of chests) and the curse room (right, has squigly lines). The curse room does unknown stuff (looks like just a normal room) but has pentagrams and a chance of having traps. The marked room is like the curse room(no picture available) except it is larger, has a circle on the floor, and markings on the walls.

Sometimes in the shop, you will find magic weapons. These weapons cost much more than normal weapons. They are just like normal weapons except they do magic (also magic staff may appear in the shop that only does magic spells). The different types of magc are the sun ray, boulder, rat, fire orb, bloodstrkie, and the cyclone. The sun ray affect will allow you to shoot a laser beam (similar to the laser trap). The boulder will allow you to throw a boulder (similar to the titan). The rat will let you shoot a blue magic rat (similar to the rat special). The fire orb will let you throw a ball of fire (similar to the wizard). The bloodstrike effect will allow you to rain magic swords from the sky. The cyclone will let you shoot a cyclone (similar to the cyclone spell). The way to notice if a sword has magc on it will be it will say magic in its name, and it will have the magic spell written in light blue letters in its discription. The other effect a weapon can have is dark. A dark weapon will add the corrupton effect to a player. The corrupton effect will make the player deal 1.5 times damage, but walk, funny (will walk only by slowly moving, or running). Dark will show up in the name of a weapon and the weapon's description will have the corruption effect in purple letters. Another effect is theiving. When you hit a monster with a theiving weapon, and the monster has gold, then there will be a slight chance that you will steal their gold (their gold will not go directly to your wallet, but will fall on the ground for you to pick up). Also a certain god will start with a theiving knife.

taunting glub
taunting s'hrim
taunting qaahl
taunting gor
taunting goloth

This guide is came out far before the current version of crawl and although some of the information may be still useful. Not all of it is still reliable.