ESO Rollplay uses a d20 (i.e. 20-sided die) system for all of its rolls. This system doesn't function like Dungeons & Dragons, so you may want to take some time to familiarize yourself with how it works.
The rolling system is built on the principle of "the GM has the final say", the same way tabletop gaming is.
There will be several times in this document where attribute modifiers will be added to rolls. Unlike Dungeons & Dragons, attribute modifiers are calculated by taking the attribute's full value minus 10. For example, an attribute score of 15 would result in an attribute modifier of +5.
In order to reduce bookkeeping, Rollplay does not use a traditional hit point system. Instead, it uses a "three strikes and you're out" injury level system. However, it is also not a system where all characters are equally durable - a character's chance to get injured is determined by their attributes and skills. The status levels are as follows:
By default, there is no way for your character to actually "die" in this system if they take too much damage, unless you ultimately decide you want character death to take place. Instead, your character will be marked as Incapacitated and will be unable to perform in combat until they are successfully healed. Incapacitated characters will still be able to actively engage in the RP portions of events if you like, so even if you’re out of combat, you can still emote.
Rolls in combat all follow the same format:
The Toughness roll to resist damage can be made tougher or easier by damage resistance or weakness.
If the character resists the incoming damage type, they roll an extra die, and take the better result.
If the character is weak to the incoming damage type, they roll an extra die, and take the worse result.
Note that in scenarios where a character could both resist and be weak to a damage type (such as a Dunmer that is a Vampire in regard to Flame damage), the weakness and resistance cancel out, and the character makes a normal roll.
In the main Elder Scrolls games, Luck is said to "affect everything you do in a small way". So what does that mean in ESO Rollplay? It means your Luck modifier has a chance to grant a lucky or unlucky roll. A character with a Luck of 10 has no modifier and thus will not receive any special rolls.
If your Luck modifer is positive, it grants a 5% chance per point for a lucky roll. On a lucky roll, an extra die is rolled, and you take the better result.
If your Luck modifier is negative, it grants a 5% chance per point for a unlucky roll. On an unlucky roll, an extra die is rolled, and you take the worse result.
Lucky/unlucky rolls can add to or cancel out the extra die added by damage resistance or weakness. An unlucky Toughness roll against a damage type you resist will cancel out to a normal roll. A lucky Toughness roll against a damage type you resist means three dice will be rolled and you take the best result!