If you enter into combat in Vegas, expect to be hurt. The combat system was designed so that combat didn't go on round after round. The emphasis of the game is on role playing and while combat plays a pivotal part of the game, it doesn't happen frequently in real time. In game time, the characters probably get into a fight everyday (you guessed it, they aren't very well liked). The fact that they will probably be hurt in every fight puts more emphasis on the fights.
Hand-to-hand.
The attacker rolls 1d10 if they are using smaller weapons like knives and 2d10 for larger weapons like swords.
The attacker's skill level, coordination bonus, and strength bonus are added to the roll.
The defender's skill level, coordination bonus, and armor resistance level are subtracted from the roll.
The result is the amount of damage done to the defender.
Ranged.
The attacker rolls 1d10 for handguns and 2d10 for long guns.
The attacker's skill level and coordination bonus are added to the roll.
The defender's armor resistance level is subtracted from the roll.
The result is the amount of damage done to the defender.
Other factors.
Magic, special weapons, and special circumstances may also modify the roll.
Armor.
Armor is listed by resistance level versus hand-to-hand weapons then ranged weapons. So, armor rl 5/10 would give five points of protection versus a sword and 10 points against a bullet.