The goal of AALL08B1 is to further refine risk stratification algorithms to intensify therapy for patients identified to be at high risk of relapse, while sparing toxicity for those highly likely to be cured. This Children's Oncology group (COG) risk-group classification protocol will provide the foundation for stratification and treatment of patients with newly diagnosed ALL and registration on this protocol is therefore required for entry onto any COG frontline ALL treatment study. Patients will be initially assigned to an induction treatment regimen based on age, white blood count (WBC), the presence of extramedullary disease and immunophenotype. Additional studies performed at local and COG reference laboratories at the time of initial diagnosis and at defined time points during induction will be used to refine pos-induction therapy. Patients with National Cancer Institute (NCI) Standard-Risk (SR) and High-Risk (HR) B-precursor ALL will be distributed among 4 risk groups following induction: Low-Risk (LR), Average Risk (AR), HR and Very High-Risk (VHR). Patients with T-cell ALL, infant ALL and Philadelphia chromosome-positive (Ph+) ALL will be treated on separated therapeutic studies.