Inclusion Criteria:

        - Diagnosis of advanced and/or metastatic solid tumors who have progressed on a standard
        therapy, are intolerant to standard of care (SoC), and/or and non-amenable to SoC.

        Participants whose tumors have known sensitizing mutations must have experienced disease
        progression (during or after treatment) or intolerance to treatment with a respective
        targeted therapy.

          -  Measurable disease according to RECIST v1.1.

          -  Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.

          -  Able to provide the most recent archival tumor tissue samples.

          -  Adequate cardiovascular, haematological, liver and renal function.

          -  Participants on therapeutic anticoagulation must be on a stable anticoagulant regimen.

          -  Women of Childbearing Potential: Agreement to remain abstinent (refrain from
             heterosexual intercourse) or use highly effective contraceptive methods.

          -  Men: Agreement to remain abstinent (refrain from heterosexual intercourse) or use
             highly effective contraceptive methods and refrain from donating sperm.

        Exclusion Criteria:

          -  Pregnancy, lactation, or breastfeeding.

          -  Known hypersensitivity to any of the components of RO7296682 and atezolizumab,
             including but not limited to hypersensitivity to Chinese hamster ovary cell products
             or other recombinant human or humanized antibodies.

          -  History or clinical evidence of central nervous system (CNS) primary tumors or
             metastases.

          -  Participants with another invasive malignancy in the last two years.

          -  Participants with known active or uncontrolled infection.

          -  Positive HIV test at screening.

          -  Positive for Hepatitis B and C.

          -  Vaccination with live vaccines within 28 days prior to C1D1.

          -  Major surgical procedure or significant traumatic injury within 28 days prior to first
             RO7296682 and atezolizumab infusion.

          -  Participants with wound healing complications.

          -  Dementia or altered mental status that would prohibit informed consent.

          -  History of Stevens-Johnson syndrome, toxic epidermal necrolysis, or DRESS (drug rash
             with eosinophilia and systemic symptoms).

          -  Active or history of autoimmune disease or immune deficiency.

          -  Prior treatment with CPIs (e.g. anti-CTLA4, anti-PD1, anti-PDL1), immunomodulatory
             monoclonal antibodies (mAbs) and/or mAb-derived therapies (approved or
             investigational) is approved.

          -  Treatment with standard radiotherapy, any chemotherapeutic agent, targeted therapy or
             treatment with any other investigational drug (defined as treatment for which there is
             currently no regulatory authority-approved indication) within 28 days or 5 half-lives
             of the drug (whichever is shorter), prior to the first RO7296882 administration on
             C1D1.

          -  Radiotherapy within the last 4 weeks before start of study drug treatment, with the
             exception of limited palliative radiotherapy (for which no wash out period is
             required).