The companions for the selected character are shown in the lower half of the Party window, located in the lower left corner of the main screen window.  If you hold your mouse over a companion's picture, its Name, Hit Points and Bind Level will be displayed.  For more information, right-click on the companion and select Info. 

There are three different ways to aquire a companion.  Sometimes, a monster encountered in the dungeon will offer to join you, but only monsters that are significantly weaker than your character(s) are likely to do so.  Companions can also be purchased from the Confinement in the city, which is a convenient way for beginning characters to get some extra help.  However, if you desire a powerful companion, you will usually have to use a Charm spell, which Binds a monster against its will to serve the character.  Only the Magi learn Charm spells for their Spellbooks; other characters will have to rely on items that cast these spells when used. 

Charming & Binding Companions 
A Charm spell, if successful, imposes a magical bond on the monster(s), the strength of which is given by the "Bind Level”.  The companion may weaken this bond over time, and if the bond becomes too weak, the monster may break free and either leave or turn on the character and attack.  The lower the Bind Level, the greater the chance of the creature breaking free and, also, the easier it is for the creature to weaken the bond.  If a Bind Level reaches 0, the creature will always break free. 

Not only do more powerful monsters require stronger bonds to keep them under control; the stronger the monster is relative to the character, the easier it will break free.  It is almost impossible for low level characters to regulate high level monsters, even with the most powerful spells; the true power of companion regulation comes with experience and guild levels. 

Increasing Bind Levels 
A character can increase (fortify) the Bind Level of a companion by either casting a Bind spell (i.e. Magi's can cast Control and Restrain), using an item, or using the Bind services in the Confinement store.  A creature with a high Bind Level in the hands of an experienced character is very unlikely to break free. 

The Bind Level inflicted on a companion during refortification depends on which spell is used and at which level the spell is cast, as does the initial Bind Level when a character Charms a monster. 

Voluntary Companions 
Depending on your character's experience and Charisma, monsters in the dungeon may offer to join your party. For these companions, the "Content Level” indicates how content the creature is. If a monster becomes too discontent, it will simply leave; it will not attack the character. Monsters are more likely to stay around if your character has high Charisma and you keep them at full hits.

Since voluntary companions have no magical bond, the ordinary Bind spells will not work on them. However, the Bind service in the Confinement store is capable of imposing bonds on voluntary companions ("converting” them), but this is very expensive.

Combat & Companions 
When in combat, your companions can use all their special abilities (such as breathe fire, stone, spit acid) against the enemy monsters, but only one spell-casting companion will be able to cast a spell each round. 

Having four companions for a single character is a great idea.  However, when two or more characters get together and each character has one or more companions, things can get confusing in battle, which can quite often result in a companion mistaking a character (and any companions they may have) for an enemy group and attack!  This can be especially dangerous with powerful magic users and fire-breathing creatures.  The possibility of a companion mistaking another character in the party and their companions for the enemy is based on the companion's experience (or character equivalent) level, which varies from creature to creature.  Creatures on the upper levels will usually have little experience in picking out the enemy and may hit other party members more often, while creatures from the lower levels will be much more advanced and experienced, and can tell the difference between a party member and an enemy in the middle of combat. 

The more bodies there are in combat, the higher the risk that another party member (and their companions) will be mistaken for the enemy.  It's recommended that the total 'body' count for an adventuring group never exceeds 6.  Any player who organizes a party of four characters with each character having four companions is going to have a really bad day - especially if some of the companions can cast high level spells or can stone their targets!! 

Handling Companions 
How dedicated are your companions? 
Monsters that offer to join are about 50% of the time dedicated to staying with the character (provided the character heals and tends to the creature as necessary).  The other 50% are just looking for some fun and could leave when they get bored or too beat up.  Keep in mind that even very dedicated companions will leave if they are badly hurt and you don't heal them. 

Regulating companions & dealing with surprise attacks 
There is a good chance that if a bound companion breaks free of their master, they will turn and attack (quite often taking other weakly bound companions with them).  This depends on the alignment of the creature versus the alignment of the character (oppositely aligned creatures will always attack), and on whether or not the creature is afraid of the character.  Evil creatures tend to attack any character when they break free. 

It is strongly recommended that a character does not take on a companion that is significantly more powerful than themselves, since there is always the slight possibility that the companion could break free of their bond and surprise attack the character and/or the party. 

You can also attack a companion: Right-click on the companion's picture and select Attack! 

If you want to get rid of a companion while in the dungeon, right-click on the companion's picture and select Kick Out.  If you kick out a Bound companion, it may choose to attack you, but most will leave peacefully. Companions cannot be traded between characters. 

Naming your Companions 
To make things a little more personal between a character and their companions, one can assign a Name to their companions by right-clicking on the picture of the companion you wish to name. 

Learning about your Companions 
Another major advantage to having a monster as a companion is that it gives the character time to learn about the monster, its abilities, strengths and weaknesses.  A character with a good ID skill (combined Intelligence, Wisdom and Guild Level) can usually deduce almost all information about a companion, using it to their advantage if they end up fighting that type of monster.  Characters with a low ID skill won't be able to learn very much about their companions and will probably have to use the ID features of the Confinement store in the City. 

It's a good idea to fully identify companions for the same reason it is to ID items.  You will be able to learn everything about them that you can, and read some general information (and knowledge) about them, which can sometimes prove to be invaluable (or at least humorous). 

There are only two ways to get a completely identified monster in the library: You must either have it as a companion and study it, or take the creature to the Confinement store and have them identify it for you. 

Healing & Resurrecting your Companions 
Characters can heal their companions while in the dungeon by casting a Heal spell from their Spellbook, or by using an item that casts such a spell.  All companions will be healed upon entering the town. Dead companions can be resurrected in the Morgue or by using standard resurrect spells in the dungeon.  Characters cannot heal or resurrect the companions of other characters in the party, since most other characters' companions are only partial to their ‘master’ or ‘friend’.  A companion that is hurt will be able to break a binding level much easier, or become very restless. 

Whenever a companion dies, you will automatically carry them - if they can be carried (ever tried to carry a giant?). In order to pick up another character, you must drop any companion you might be carrying. If a companion dies and you are already carrying one, the companion with the most hits will be carried. A character will never drop a character to carry a dead companion. If a dead companion gets dropped (or wasn't carried in the first place), it's gone forever.

Moving & Reorganizing your Companions  
You can move and reorganize your companions by dragging and dropping the companion picture onto another companion slot.  This allows the player to place stronger companions in front, and weaker (or spell-casting) companions in the back. 

Selling your Companions 
One bonus to collecting companions is the ability to Sell them in the city for profit.  The Confinement will pay handsome prices for powerful creatures.  On the flip side, the more powerful creatures are harder to contain and regulate than the weaker ones.