Although uncommon in the civilized systems of the Gravity Age, biological warfare has never fully disappeared. Particularly on frontiers such as the Verge, especially ruthless or desperate people have been known to use bio-agent ammunition to get the job done.

Bio-agent ammunition contains a miniscule amount of a biological weapon inside an insulated chamber within each round. Use of bio-agent rounds imposes a –1 penalty to damage. Any living creature struck by a bio-agent round, however, is injected with a poisonous compound with effects identical to cyanogen gas (DC 19, 1d4 Dex, 2d4 Con).