Bacteria employ various antiphage defense systems to counter phage infection, often depleting cellular nicotinamide adenine dinucleotide (NAD+) to impede phage replication. This study identifies a novel strategy where a substantial fraction of phages can reconstitute NAD+ from its degradation products, ADP-ribose (ADPR) and nicotinamide, in infected cells. The authors describe two pathways: NAD+ reconstitution pathway 1 (NARP1) and NAD+ reconstitution pathway 2 (NARP2). NARP1 involves two enzymes: an ADPR-PP synthetase (Adps) that phosphorylates ADPR to ADPR-PP, and a Nicotinamide ADPR-transferase (Namat) that conjugates ADPR-PP and nicotinamide to form NAD+. Phages encoding NARP1 can overcome multiple NAD+-depleting defense systems, including Thoeris, DSR1, DSR2, SIR2-HerA, and SEFIR. Phylogenetic analyses show that NARP1 is primarily encoded in phage genomes, suggesting a phage-specific function in countering bacterial defenses. NARP2, another NAD+ reconstitution pathway, uses different metabolites (PRPP and ADPR-PP) to generate NAD+ and is encoded in a smaller fraction of phage genomes. These findings reveal a unique immune evasion strategy where viruses rebuild molecules depleted by defense systems, thereby overcoming host immunity.Bacteria employ various antiphage defense systems to counter phage infection, often depleting cellular nicotinamide adenine dinucleotide (NAD+) to impede phage replication. This study identifies a novel strategy where a substantial fraction of phages can reconstitute NAD+ from its degradation products, ADP-ribose (ADPR) and nicotinamide, in infected cells. The authors describe two pathways: NAD+ reconstitution pathway 1 (NARP1) and NAD+ reconstitution pathway 2 (NARP2). NARP1 involves two enzymes: an ADPR-PP synthetase (Adps) that phosphorylates ADPR to ADPR-PP, and a Nicotinamide ADPR-transferase (Namat) that conjugates ADPR-PP and nicotinamide to form NAD+. Phages encoding NARP1 can overcome multiple NAD+-depleting defense systems, including Thoeris, DSR1, DSR2, SIR2-HerA, and SEFIR. Phylogenetic analyses show that NARP1 is primarily encoded in phage genomes, suggesting a phage-specific function in countering bacterial defenses. NARP2, another NAD+ reconstitution pathway, uses different metabolites (PRPP and ADPR-PP) to generate NAD+ and is encoded in a smaller fraction of phage genomes. These findings reveal a unique immune evasion strategy where viruses rebuild molecules depleted by defense systems, thereby overcoming host immunity.