1. Notes

Combat Rules

Rules
OSE
OSE Rules
  1. Declare spells and retreats
  2. Initiative: Each side rolls 1d6.
  3. Winning side acts:
    1. Monster morale
    2. Movement
    3. Missile attacks
    4. Spellcasting
    5. Melee attacks
  4. Other sides act: In initiative order.

"Chop when they drop"

Fighters, dwarves, and elves get a free follow-on attack whenever they drop an enemy and can continue to make attacks in this way up to their level. So a 3rd level fighter can make up to three attacks, as long as his first two attacks each killed an enemy.

Healing

A divine caster can expend any memorized spell or take one hit die of damage to cast a weaker version of cure light wounds that heals for 1d4 instead of 1d6+1 hit points.

Shields Shall Splinter

A shield can take the full force of a blow and is destroyed in the process.

Hit Points

Reroll all HD upon level up. If total is higher, take the new number. Reroll 1's.

Dying & 0 Hit Points

When you reach 0 HP, you fall to the ground, incapacitated and wounded. Note the amount of HP you'd be below zero.

You get a total of 3 'death saves' per character. Original rules don't have any (0 hp = YOU DIED), so see it as a blessing.

Make a Saving Throw v. Death. If you fail, you die. If you succeed, you are unconscious. You awaken in xd4 hours with 1 HP, in which the x is the amount of hp you are below zero.

Criticals

Max damage on a nat 20, 1's are an auto-miss.

Helmets

Grant +1 AC and cost 10 gp.

Defense Rolls

The players roll their characters’ attacks as normal, but you don’t roll for their opponents.

Instead, when a character is targeted by an attack, the player makes a defense roll.

A defense roll has a bonus equal to the character’s AC − 10.

The DC for the roll equals the attacker’s attack bonus + 12.

On a successful defense roll, the attack misses because it was dodged, absorbed by the character’s armor, and so on.

If a character fails a defense roll, the attack hits.
If the attacker would normally have advantage on the attack roll, you instead apply disadvantage to the defense roll, and vice versa if the attacker would have disadvantage.
If the defense roll comes up as a 1 on the d20, then the attack is a critical hit.
If the attacker would normally score a critical hit on a roll of 19 or 20, then the attack is a critical hit on a 1 or 2, and so forth for broader critical ranges.