PARLEY

In order to determine the intent of a possibly friendly or neutral monster or to pass along your intentions or desires, some form of communication is necessary. Speech might do for human-types, as the Common tongue is known by most. But what of an encounter with a giant, blink dogs, or dozens of similar creatures? An open and raised right hand is possible, and simply refraining from hostile moves will possibly allow for further exchange. Remember though, that you cannot bribe a band of ogres to allow you to pass through unless you can communicate clearly.

Upon encountering another party, the party with initiative can always elect to attempt some form of communication. 

This can be a friendly gesture, a throwing down of arms, offering of treasure, or some spoken word or phrase. Just what this effect will be is determinable only by the DM considering the prevailing circumstances. It is safe to say that a group of elves attempting to parley with a red dragon will find their efforts generally unsuccessful unless they also have some obvious advantage which the dragon is aware of. It is common for player characters to attack first, parley afterwards. It is recommended that you devise encounters which penalize such action so as to encourage parleying attempts which will usually be fruitless, of course!

Any intelligent creature which can be conversed with will react in some way to the character that is speaking.

 Reaction is determined by rolling percentile dice, adjusting the score for Charisma and applicable loyalty adjustment as if the creature were a henchman of the character speaking, and the modified score of the percentile dice is compared to the table below: