====== Dominions Random Number (DRN) ======

Most skill checks use a **Dominions Random Number**, or a DRN. This includes virtually all Damage rolls, [[attack skill|Attack]] rolls, [[Precision|Missile Hit]] rolls, and so on.

The DRN is two six-sided dice. A lower-case "drn" is one six-sided die. Any dice roll described as an "XdY" (i.e. 1d4) without saying it's open-ended is closed.

What makes this different from regular six-sided dice rolls? Well, Dominions Random Number dice **explode**; if you roll a **6**, you make it a **5**, and then you **roll that die again**. The extra roll is added to your total. You continue to roll until you stop rolling 6's. This is called an "open-ended" roll in-game, while regular rolls are known as "not open-ended" or "closed".

==== Understanding the DRN ====

Due to how the DRN works, there are few skill checks that are utter guarantees, and determining what the result of a roll will be is even more difficult.

=== drn Math (One Die) ===

You could zoom in on the odds of an open-ended six-sided die's results an infinite number of times, but let's just say you only expand twice at most:

<WRAP group>
<WRAP half column>
**Out of 216 Closed Rolls...**
  * 36 will be 1's (16.67%)
  * 36 will be 2's (16.67%)
  * 36 will be 3's (16.67%)
  * 36 will be 4's (16.67%)
  * 36 will be 5's (16.67%)
  * 36 will be 6's (16.67%)
**Average: 3.5**

</WRAP>

<WRAP half column>
**Out of 216 Open Rolls...**
  * 36 will be 1's (16.67%)
  * 36 will be 2's (16.67%)
  * 36 will be 3's (16.67%)
  * 36 will be 4's (16.67%)
  * 36 will be 5's (16.67%)
  * 6 will be 6's (2.778%)
  * 6 will be 7's (2.778%)
  * 6 will be 8's (2.778%)
  * 6 will be 9's (2.778%)
  * 6 will be 10's (2.778%)
  * 1 will be an 11 (0.463%)
  * 1 will be a 12 (0.463%)
  * 1 will be a 13 (0.463%)
  * 1 will be a 14 (0.463%)
  * 1 will be a 15 (0.463%)
  * 1 will be at least 16 (0.463%)
**Average: 3.930** (if the 16+ roll is ignored; **~4** otherwise)

</WRAP>
</WRAP>

=== DRN Math (Two Dice) ===

<WRAP group>
<WRAP half column>
**Out of 1296 Closed Rolls...**
  * 36 will be 2's (2.778%)
  * 72 will be 3's (5.556%)
  * 108 will be 4's (8.333%)
  * 144 will be 5's (11.11%)
  * 180 will be 6's (13.89%)
  * 216 will be 7's (16.67%)
  * 180 will be 8's (13.89%)
  * 144 will be 9's (11.11%)
  * 108 will be 10's (8.333%)
  * 72 will be 11's (5.556%)
  * 36 will be 12's (2.778%)

**Average: 7**
</WRAP>

<WRAP half column>
**Out of 1296 Open Rolls...**
  * 36 will be 2's (2.778%)
  * 72 will be 3's (5.556%)
  * 108 will be 4's (8.333%)
  * 144 will be 5's (11.11%)
  * 180 will be 6's (13.89%)
  * 156 will be 7's (12.04%)
  * 132 will be 8's (10.19%)
  * 108 will be 9's (8.333%)
  * 84 will be 10's (6.481%)
  * 60 will be 11's (4.63%)
  * 51 will be 12's (3.935%)
  * 42 will be 13's (3.241%)
  * 33 will be 14's (2.546%)
  * 24 will be 15's (1.852%)
  * 15 will be 16's (1.157%)
  * 12 will be 17's (0.926%)
  * 8 will be 18's (0.617%)
  * 7 will be 19's (0.54%)
  * 3 will be 20's (0.231%)
  * 4 will be 16's with another roll (0.309%)
  * 4 will be 17's with another roll (0.309%)
  * 4 will be 18's with another roll (0.309%)
  * 4 will be 19's with another roll (0.309%)
  * 4 will be 20's with another roll (0.309%)
  * 1 will be a 20 with two more rolls (0.072%)
**Average: ~8** (assuming the extra rolls add either drn average)

</WRAP>
</WRAP>

===== Dueling DRNs =====

//Most// DRN rolls are in opposition to another DRN roll. The Damage roll, for example, is opposed by a [[Protection]] DRN roll. The Attack roll is opposed by a [[Defence Skill|Defence]] roll, the Penetration roll to make many [[magic]] spells work is opposed by a [[Magic Resistance]] roll, and so on. In these three cases, a base value (typically matching the name of the roll) is added on to whatever the result is, and what happens next is determined by the value.

  * A hit is considered to hit if the Attack roll **beats** (doesn't tie with) the Defence roll, at least without any Parry bonus.
  * A hit is considered to **do damage** if the Damage roll **beats** the Protection roll. The difference determines the damage done, but some attacks have "side effects" (such as the [[poison damage|poison]] of an ??Asp?? bite) that only check if the hit did damage at all.
  * A Penetration roll succeeds if it **at least ties with** the opposing Magic Resistance roll.