This guide is a working reference to collateral attack on criminal convictions and sentences, written for counsel, clinics, and self-represented petitioners. It distinguishes direct appeal from collateral review, sets out the available vehicles in state and federal court, and explains why the record made in state post-conviction proceedings now determines nearly everything that follows. Substantive chapters treat the three claims that carry successful petitions — ineffective assistance, suppressed favorable evidence, and newly discovered evidence — each with the governing standard, the proof required, and the patterns that succeed. Procedural chapters cover the one-year limitation and its triggers and tolling, exhaustion and fair presentation, procedural default and its exceptions, deference to state adjudications, the record limitation, evidentiary hearings, certificates of appealability, and successive petitions. Further chapters address sentencing-only claims, sentence modification, DNA testing, immigration vacatur, clemency, and relief from collateral consequences. Drafting chapters set out what a petition must contain and the affidavit practice that determines whether a hearing is granted. Reference tables close the guide with every authority linked.