By pressing USE (default E) button as a Counter-Terrorist, the triggered hostage will follow the Counter-Terrorist and $150 will rewarded for leading the hostage. By rescuing a hostage, $1000 will be rewarded to the Counter-Terrorist that rescued the hostage. In matches, funds will be reduced if the players injured or killed them. The money reduced is vary from how much damage caused, but all 50 hp equals to $2500.
When a Counter-Terrorist is near a hostage, the hostage will wave and shout for help. However, if there's a Terrorist camping near to the hostage, he will be silent and do nothing when a Counter-Terrorist is nearby.
Usually when there are no Terrorists camping, the hostages will automatically try to find a way to escape by slowly sneaking to the Hostage rescue zone. When all of them have escaped, a message will pop up and a sound will play saying "Hostages have escaped".
When spotted by a Terrorist while escaping, a hostage will be stunned and retreat back to the hostage room slowly.
Sometimes, hostages will get stuck while following you due to bot navigation mesh. This usually happens in old Counter-Strike maps.
When you point your gun at a hostage, he will react in fear. The hostage's sentences can express that he is scared, such as "What do you want from me?" or his bravery, such as "I'm not gonna tell you anything".
Hostages react to grenades and gunshots nearby; they will splutter when they're exposed to the smokes from the Smoke Grenade for instance. In addition, they will also express shock when their colleague/s are killed in their vicinity.