The paper aims at defining the core patterns for biochar-based remediation of soils contaminated after hostilities. The main ecological problem of combat-impacted zones is multicomplexes of soil pollution and degradation as well as co-contamination by potentially toxic elements (PTEs) and energetic compounds (ECs). Biochar produced from different feedstocks, including woody (oak, ash) and non-woody (digestate) biomass, were analysed for ash and carbon content, elemental composition and microstructure. Based on the purpose of using biochar for soil remediation and specification of contaminated soils laboratory biochar samples were produced by slow pyrolysis (600°C, 5–7°C min⁻¹, 2 h). Obtained results showed high ash contents in wood and digestate-derived biochars (≈33–36%) and elevated organic carbon in digestate-derived biochar, indicating strong sorption capacity for organic explosives (e.g., RDX) and capacity for heavy-metal immobilization. Review of main mechanisms for heavy metals and explosives degradation using biochar highlighted that core pathways like pore filling, π–π and hydrophobic interactions, electrostatic adsorption, cation exchange, surface complexation, redox transformations and microbially mediated degradation directly depend on feedstock, pyrolysis parameters and soil chemistry. Based on the study results pyrolysis production parameters were suggested (optimal pyrolysis window ~500–600°C; slow heating; feedstock mixes). These findings highlight biochar-based technologies as promising approach to remediation of military-impacted soils, but field trials are needed to prove efficacy, long-term stability and ecological safety.