If an opponent does damage to you, they become Infected. An Infected player takes 5 damage at the end of each subsequent turn. They may burn 5 to remove the Infection.
Raven
Underwarez
When you damage an opponent, you gain 5 Bits.
Raven
Packet Sniffer
Bits are assigned and declared in two stages; those being spent by opponents to activate Programs, then the rest.