Yidam is a type of deity associated with tantric or Vajrayana Buddhism said to be manifestations of Buddhahood or enlightened mind. During personal meditation (sādhana) practice, the yogi identifies their own form, attributes and mind with those of a yidam for the purpose of transformation. Yidam is sometimes translated by the terms "meditational deity" or "tutelary deity". Examples of yidams include the meditation deities Chakrasamvara, Kalachakra, Hevajra, Yamantaka, and Vajrayogini, all of whom have a distinctive iconography, mandala, mantra, rites of invocation and practice. In Vajrayana, the yidam is one of the three roots of the inner refuge formula and is also the key element of deity yoga since the 'deity' in the yoga is the yidam. Etymology Yidam is said to be a contraction of Tib. yid-kyi-dam-tshig, meaning "samaya of mind" or in other words, the state of being indestructibly bonded with the inherently pure and liberated nature of mind. This is said to be the act that balances energies coursing within the pranic ida and pingala channels in the subtle bodies of both participants. The practitioner focuses on and identifies with the resultant Buddha-form or 'meditation deity', the yidam (Tibetan) associated with IDA channel. The Sanskrit word or a compound of iṣṭa (desired, liked, reverenced) + devatā (a deity or divine being) is a term associated with yidam in many popular books on Buddhist Tantra but has not been attested in any Buddhist tantric text in Sanskrit. Three Roots The yidam appears as one of the Three Roots in the Tibetan Buddhist 'Inner' refuge formulation. The iconography of the yidam may be 'peaceful', 'wrathful' (Tibetan tro wa) or 'neither peaceful or wrathful' (Tibetan: shi ma tro), depending on the practitioner's own nature. The yidam represents awakening and so its appearance reflects whatever is required by the practitioner in order to awaken. The guru will guide the student as to which yidam is appropriate for them and then initiation into the mandala of the Ishta-deva is given by the guru, so that deity yoga practices can be undertaken. In essence, the mindstream of the guru and the yidam are indivisible. The yidam is considered to be the root of success in the practice. In East Asian Buddhism The Vajrayana traditions of China, Korea and Japan, while smaller and less prominent than Indo-Tibetan tantric Buddhism, are characterized in part by the utilization of yidams in meditation, though they use their