Every infantry unit and crew has a Biological and Chemical resistance number. This is listed as X / Y, where X is the Biological resistance, and Y is the Chemical resistance. We usually refer to Biological and Chemical Weapons as BioChem Weapons.

Note that BioChem Attacks target areas, not units. As such, units are only exposed when beginning their turn in an area hit by chemical weapons, or moving into an area hit by chemical weapons. Infantry are always considered exposed, depending on their level of protection. Tanks are only exposed if they spend 1/2 of their movement in a contaminated area.

One half of a tanks movement is considered by how far it actually moved this turn, not its overall speed, or number of movement points spent. If a tank spends 4 movement points to move two inches up a hill, it will be exposed by one contaminated hex. If it had moved 3 inches (spending 5 or 6 movement points) it would not have been exposed by the 1 hex of gas.

If you are exposed to a BioChem Weapon and its level is higher than your protection level, you are affected. To represent this, a BioChem Attack affects 1d6 people for each level it is above their protection. It does this every round they remain exposed until they are all affected. For example, if your infantry unit has level 3 Chemical protection, and is hit by level 5 Chemical agents, 2d6 men will become affected per turn.

BioChem agents in are typically delivered by artillery attacks. They effect a one hex/inch diameter area. They will then disperse to a 3 inch diameter area on the second turn. They will typically last for the entire course of the game. For more on dispersal, see the "Smoke and Wind" optional rule.

Once affected, you will eventually succumb to the effects unless you undergo cleaning. Cleaning is not something that can happen during the time-span of a typical game. Listed with the Agent is a Delay number. This is the number of rounds before the effects kick in, and the soldiers succumb to the BioChem weapon. While this does not necessarily mean death, it does mean they are out of the game.

Note that for every round you remain exposed to a weapon that effects you, you subtract 2 from the Delay number. For example, a unit affected by a weapon with a Delay of 10 would normally take 10 rounds before succumbing. If they stay in the exposed area, they will succumb in 5 rounds, not 10.

Level 1 protection would be considered a gas mask. Level 2 protection is a full body suit.

One Final Note: We do not have rules to force you to avoid moving your troops into areas that will expose them to these weapons. But please, use common sense in this area.