The basic way combat goes in Earthdawn is everyone declares their actions, everyone then rolls their initiative step, and then actions are resolved, with the highest initiative rolls going first.
Physical attacks are made with a difficulty number of your target's Physical Defense. This can be ranged or melee combat, armed or unarmed. If you succeed, you roll damage, which is your Strength step plus your weapon's Damage step, and is reduced by your target's Physical Armor, including his shield. An Excellent Success on your attack test will negate armor. If you do not have any Talents or Skills for physical attack, then you can roll your Dexterity Step for Melee Weapons, Missile Weapons, Throwing Weapons, or Unarmed Combat.
You can also attempt to Avoid Blows. This is available as both a talent and a skill, but if you have neither, you may roll your dexterity step. Any attempt to avoid a blow causes 1 point of strain, and if you fail, you will be Knocked Down.
Blindside Attack: Blindside attacks give a +2 step bonus to the attack. The attacker must be able to see the target. The bonus also applies to blind, surprised, and ambushed targets.
Darkness: Natural darkness will cause a -3 step penalty to all tests except Knockdown. It can be worse for magical darkness, or reduced with Low Light Vision or Heat Sight.
Harried: A character is Harried when there are four or more melee attackers on one. A Harried character has a -2 step penalty to all tests.
Knocked Down: If you are knocked down, your Physical Defense and Spell Defense are both lowered by 3, and all actions are at -3 steps. Standing back up requires a full action.
Shooting Into a Melee: Add the number of people between the Shooter and the Target to the Target's Physical Defense. If the Shooter misses, compare his Attack Test result to the Physical Defenses of everyone between him and his target. The attack will hit the one closest to the shooter with a Physical Defense equal to or lower than the Attack Test result, and that one will take normal damage.
Surprise: If you are in a situation where you could be surprised, the GM will make a Perception test for you. If you are surprised, your Physical Defense and Spell Defense are lowered by 3. At the GM's option, your Social Defense may also be lowered by 3. Nor can you act while you are surprised. Surprise lasts only until the end of the round.
Wounds: Wounds have two effects. First, they slow healing of damage. Reduce the result of any Recovery Tests you make by the number of Wounds you have, though not below 1. Second, they hinder your abilities. For each Wound after the first, reduce the step number of all tests except Recovery tests by one. Also, any time you take a Wound, you must check to see if you get Knocked Down. In most cases, tests to avoid being Knocked Down are strength tests. The difficulty number for the Knockdown Test is the amount of damage you took, minus your Wound Threshold, plus 3.
You will take one Wound any time you take damage equal to or greater than your Wound Threshold in ONE attack. This includes stun attacks. Some spells and magical effects will cause multiple Wounds, but these are rare. Wounds are slow to heal naturally. You normally cannot heal Wounds unless you have healed all Damage you have taken (except for Permanent Damage from blood magic), and only the first Recovery Test each day will normally heal a Wound.
All combat options must be declared with actions.
Aggressive Attack: Aggressive Attack is an option for melee attacks only. You pay one point of strain (i.e., voluntary damage), and your attack and damage tests each get a 3 step bonus. You must pay the strain for each attack test you make, if you make more than one in a round. The disadvantage to Aggressive Attack is that every attack you take is also made with a three step bonus. Aggressive Attack cannot be combined with defensive melee options.
Attack to Knock Down: This may be used with any melee attack. You roll your attack and damage normally. While the target does not take any damage, they must make a knockdown test with a target number equal to your damage result, reduced only by their physical armor, regardless of their Wound Threshold. If they fail, they are knocked down.
Attack to Stun: This may be used with any melee attack except for Claw Shape. You cannot kill somebody by attacking to stun, though you can cause Wounds. However, stun damage greater than unconsciousness rating causes unconsciousness and greater than death rating causes a coma which will last until damage is less than the unconsciousness rating. The stunned character adds his willpower step to the recovery step when making the first recovery test after taking stun damage.
Called Shot: Called Shots can be made with any attack. Unless using the Called Shot skill or talent, the test will be at -3 steps. Success means that the attack hits in the general area called, though I tend to be pretty generous with this, particularly in dramatic climaxes.
Defensive Stance: You concentrate very hard on defense, at the cost of not concentrating on anything else. Physical Defense is +3, but all tests except for knockdown tests are at -3 steps.
Giving Ground: This is a defensive melee option that can only be used with Unarmed Combat or Melee Weapons. It costs 1 point of strain. You can retreat up to one yard per rank in Melee Weapons or Unarmed Combat. For each yard you retreat, you gain +1 to your Physical Defense. Whoever has the highest initiative -- either you or your attacker(s) -- controls the direction of your retreat. You will not retreat over a cliff, into a river or pool of lava, or into any other hazard.
Going Inside a Shield: The attacker subtracts the armor rating of his opponent's shield from his Initiative. If the attacker has higher initiative, he completely negates his opponent's shield. If not, the attack is at -2 steps. This option is available for melee attacks, ranged attacks, and spellcasting attacks (in which case the shield's mystic armor is subtracted from the attacker's initiative, instead of physical armor.)
Mounted Attacks: When attacking from a charging mount, add the mount's Strength step to the damage step. Mounted characters may have higher ground.
Staying Mounted: After rolling damage for a charge attack, the rider must make a Strength or Charge test against his target's Toughness step. If he succeeds, nothing happens. If he fails, he either drops his weapon, or (if using a spear or lance) he is unmounted and takes step 5 falling damage.
Splitting Movement: This is available to mounted and flying characters. Half of the combat movement is made before the attack, and half after, and there is a -2 penalty to Physical Defense. However, only those with initiative as high or higher than the one splitting movement can attack him in melee.
Setting Against a Charge: If a footman has initiative as high as a charging rider, and a polearm or spear at least 7' long, he may set against the charge, automatically gaining initiative over the rider. If he hits, the rider takes damage equal to his mount's Strength step plus the weapon's Damage step. A Good success on the attack unmounts the rider, and he takes falling damage of Step 5.