Initiative in combat is based on poker cards, used as Action Cards. You go in order from aces to deuces. If there is a tie, then suits are done in reverse alphabetical order: spades, hearts, diamonds, and finally clubs. If you draw a Joker, you can go at any point in the round and you add a +2 to all Trait and damage rolls for the round. If an enemy draws a Joker, they get a Benny to put in the general pool. There are Edges and Hindrances that can also change your initiative, making you faster or slower. Cards are drawn at the start of every round, not just the start of combat.
During your turn, you can perform one Action. Additional actions—up to 3—can be performed, but each one inflicts a cumulative -2 penalty on all of the actions taken. You can also perform free actions, such as speaking a few sentences, dropping an item, or falling prone. You can also move up to your Pace as a free action, and perform your action at any point during the movement without penalty. You can also Run, which gives a -2 penalty to all actions during the turn, but gives you an extra d6 of movement.
When Fighting in melee combat, your target number isn't a 4; instead your opponent's Parry skill is your target number. Ranged attacks use the Shooting skill, and is against the default 4 target number, but can be affected by cover and distance.
On a hit, your opponent rolls damage against your Toughness. Toughness is based on the Vigor attribute and any Armor. If it succeeds, you are Shaken. Shaken is a representation of being nicked, bruised, or rattled, but not really hurt. While Shaken, you can only take Free Actions, including trying to overcome your Shaken status. Overcoming Shaken requires a successful Spirit roll, or you can spend a Bennie (you can spend it even if it's not your turn). Also once you are Shaken, every additional hit becomes a Wound. If the damage roll is a Success and a Raise, then you're Shaken and take a Wound. Each Wound adds -1 penalty to all rolls, until you get Incapacitated after three wounds. You can make a Soak roll with Vigor to try to negate some damage, but it costs a Benny.
Fighting and Shooting aren't the only options, of course. Your talents may instead be stealth, taunting your foes, or running away to better cover. Some other actions are listed below.