The Refuges and Precepts are not mantras, but they are chanted in a mindful way in order to connect our minds with the goal of spiritual awakening. So they have the same function as mantras, ultimately.
The chant is in several parts.
The words “Namo tassa bhagavato arahato sammāsambuddhassa” are chanted three times. This is a salutation to the historical Buddha, and it means “Homage (namo) to him (tassa) the blessed one (bhagavato) the worthy one (arahato) the fully and perfectly awakened one (sammāsambuddhassa).
Since it was originally an orally transmitted tradition, Buddhism likes repetition, especially three-fold repetition.
Then comes the threefold refuge forumula:
Buddhaṃ saraṇaṃ gacchāmi.
Dhammaṃ saraṇaṃ gacchāmi.
Saṅghaṃ saraṇaṃ gacchāmi.
To the Buddha for Refuge I go.
To the teachings for refuge I go.
To the spiritual community for refuge I go.
This is then repeated a second and third time, thus:
Dutiyampi buddhaṃ saraṇaṃ gacchāmi.
Dutiyampi dhammaṃ saraṇaṃ gacchāmi.
Dutiyampi saṅghaṃ saraṇaṃ gacchāmi.
Dutiyampi means “for a second time …”
Tatiyampi buddhaṃ saraṇaṃ gacchāmi.
Tatiyampi dhammaṃ saraṇaṃ gacchāmi.
Tatiyampi saṅghaṃ saraṇaṃ gacchāmi.
Tatiyampi means “for a third time…”
Then come the five precepts, which are five ethical training principles that we undertake to put into practice in our lives. These are:
Pāṇātipātā veramaṇī sikkhāpadaṃ samādiyāmi
Adinnādānā veramaṇī sikkhāpadaṃ samādiyāmi
Kāmesumicchācāra veramaṇī sikkhāpadaṃ samādiyāmi
Musāvādā veramaṇī sikkhāpadaṃ samādiyāmi
Surā-meraya-majja pamādaṭṭhānā veramaṇī sikkhāpadaṃ samādiyāmi
These are not commandments. Each precept contains the words sikkhāpadaṃ samādiyāmi, which mean “I undertake the training principle.” So there’s no compulsion; these are practices taken on in order to train the mind to be more compassionate and mindful, and not rules undertaken in order to avoid punishment.
In order, these precepts mean:
I undertake the training principle of abstaining from taking life.
I undertake the training principle of abstaining from taking the not-given.
I undertake the training principle of abstaining from sexual misconduct.
I undertake the training principle of abstaining from false speech.
I undertake the training principle of abstaining from intoxication.
The precepts end with a three-fold “Sādhu!”, which means “Good!” or even “Alright!”
The early Buddhist tradition, as it’s been handed down to us, tends to emphasize what we shouldn’t do, although some of the suttas (Buddhist discourses) also stress the positive counterparts of the precepts. In order to acknowledge what we’re trying to cultivate, as well as what we’re trying to avoid, in the tradition I practice within (the Triratna Buddhist Community) we add five “positive precepts,” which are also part of the chant.
With deeds of lovingkindness, I purify my body.
With open-handed generosity, I purify my body.
With stillness, simplicity, and contentment, I purify my body.
With truthful communication, I purify my speech.
With mindfulness, clear and radiant, I purify my mind.
This sequence of chants are often performed collectively at the start of a period of practice, and especially at the start of the day, as a kind of “mission statement.”