3rd Tone, 3rd Tone Combination Rule

One important rule is when two 3rd tone syllables come one after the other i.e.

As in the word lăobăn which is the Pinyin for boss. 

When a 3rd tone is followed by another 3rd tone, the first 3rd tone changes to a 2nd tone.
This can be shown graphically:

This rule applies to words as well as a group of words. It even applies to probably the first word you learnt in Mandarin Chinese.

Nĭ hăo is the Pinyin with accents, but it is pronounced as ní hăo.