This excerpt taken from the ATVI 10-Q filed Nov 7, 2007.
Chart of Compensation Paid to Non-Employee Directors
*The annual stock option grants and annual restricted stock unit awards will vest ratably every three months over the one-year period from the date of grant.
**The stock option grants and restricted stock unit awards granted in connection with a directors initial election to the board or his or her tenth year of continuous service on the board (which are granted in lieu of the annual grant to the person in that year) will vest ratably every three months over the two-year period from the date of grant.
In addition to the compensation listed in the table above, non-employee directors are reimbursed for expenses incurred in attending board, committee and stockholder meetings.