D&Dtools1

Casting this spell attempts a dangerous act: to lure a spirit to a specifically prepared trap, which must lie within the spell's range.
The called spirit is held in the trap until it agrees to perform one service in return for its freedom.
To create the trap, you must use a magic circle spell, focused inward.
The type of spirit to be bound must be known and stated.
If it has a specific, proper, or given name, this must be used in casting the spell.
The target spirit must attempt a Will saving throw.
If the saving throw succeeds, the creature resists the spell.
If the saving throw fails, the spirit is immediately drawn to the trap (spell resistance does not keep the creature from being called).
The spirit can escape from the trap with a successful SR roll, dimensional travel, or a successful Charisma check (DC 15 + 1/2 the caster's level + the caster's Charisma modifier).
It can try each method once per day.
If it breaks loose, it can flee or attack you.
A dimensional anchor cast on the spirit prevents its escape via dimensional travel.
You can also employ a calling diagram (see Calling in the Player's Handbook) to make the trap more secure.
If the spirit does not break free of the trap, you can keep it bound for as long as you dare.
You can attempt to compel the spirit to perform a service by describing the service and perhaps offering some sort of reward.
You make a Charisma check opposed by the spirit's Charisma check.
The DM then assigns a bonus based on the service and reward, from +0 to +6.
This bonus applies to your Charisma check.
If the spirit wins the opposed check, it refuses service.
You can make new offers, bribes, and the like or offer again the old ones every 24 hours.
You can repeat this until the spirit promises to serve, until it breaks free, or until you decide to get rid of it by means of some other spell.
Impossible demands or unreasonable commands are never agreed to.
If you roll a 1 on the Charisma check, the spirit breaks free of the binding and can escape or attack you.
Once the requested service is completed, the spirit need only so inform you to be instantly sent back whence it came.
The spirit might later seek revenge.
If you assign some open-ended task that the spirit cannot complete though its own actions (such as "Wait here" or "Defend this area against attack"), the spell remains in effect for a maximum of one day per caster level, and the spirit gains an immediate chance to break free.
Note that a clever recipient can subvert some instructions.
When you use a calling spell to call an air, chaotic, earth, evil, fire, good, lawful, or water creature, it is a spell of that type.
For example, lesser spirit binding is a water spell when you cast it to call a water elemental.