Why Dice Matter in Dungeons and Dragons
Dice are the heartbeat of every tabletop RPG. They determine whether your rogue's sneak attack lands, whether your wizard resists the dragon's fire, and whether your bard convinces the guard to look the other way. Understanding how each die works and when to roll it is the first step from beginner to confident player.
A virtual dice roller like the Decide Dice roller lets you roll every standard polyhedral die from your phone or laptop, which is perfect for remote sessions, spontaneous games, or those nights when someone forgot their dice bag.
Dice Notation: What Does 1d20+5 Mean?
Tabletop RPGs use a shorthand called dice notation. The format is XdY plus or minus a modifier. X is the number of dice to roll, Y is the number of sides on each die, and the modifier is a bonus or penalty added to the result.
For example, 1d20+5 means roll one twenty-sided die and add five to the result. 3d6 means roll three six-sided dice and sum them. 2d8+3 means roll two eight-sided dice, add them together, and add three. Once you understand this notation, every rulebook and spell description becomes readable.
Each Die Explained
The D20 is the most rolled die in D&D. It handles attack rolls, saving throws, ability checks, and death saves. When the dungeon master asks you to roll, they almost always mean a D20.
The D4 deals small damage — daggers, healing potions, and minor spells. The D6 is for shortswords, greatclub damage, and character stat generation (roll 4d6 and drop the lowest for each ability score). The D8 covers medium weapons like longswords and battleaxes. The D10 is used for cantrip damage and percentile rolls when paired with a second D10. The D12 is the barbarian's hit die and is used for greataxe damage. The D100 (or two D10s rolled as percentile) is for random encounter tables and wild magic surges.
Advantage and Disadvantage
Advantage means roll two D20s and take the higher result. Disadvantage means roll two D20s and take the lower. This mechanic replaced the complex list of plus-one and minus-two modifiers from earlier editions, making the game faster and more intuitive.
You get advantage when you have a clear edge — shooting at a close target, attacking from hiding, or when an ally is helping you. You get disadvantage when something hinders you — shooting at long range, attacking while prone, or trying to see in darkness without darkvision. Advantage and disadvantage cancel each other out, and you never roll more than two dice regardless of how many sources of advantage or disadvantage you have.
Critical Hits and Fumbles
A natural 20 on a D20 attack roll is a critical hit. You roll the damage dice twice and add your modifier once. A natural 1 is a critical fumble, which usually means something goes wrong — your weapon breaks, you hit an ally, or you trip. The dungeon master decides the exact consequence.
Critical hits do not double the modifier — only the dice. So a longsword attack that normally deals 1d8+3 damage deals 2d8+3 on a critical hit. Some tables play with house rules that double the modifier too, but that is not the official rule.
Using a Virtual Dice Roller for D&D
An online dice roller is especially useful for rolling multiple dice at once. If a fireball deals 8d6 damage, rolling eight physical dice and adding them up takes time. A virtual roller returns all eight results and the total instantly, which keeps combat moving.
The Decide Dice roller supports up to ten dice at once with any die type from D4 to D100. You can also use custom labels to turn a D6 into a yes-or-no-maybe die, or a D20 into a random encounter table. This makes the tool useful far beyond standard combat rolls.
Frequently Asked Questions
What does 1d20+5 mean in D&D?
It means roll one twenty-sided die and add five to the result. The number before the 'd' is how many dice to roll, the number after is the sides, and the modifier is added to the total.
How does advantage work with a D20?
When you have advantage, roll two D20s and take the higher result. With disadvantage, roll two D20s and take the lower. If you have both advantage and disadvantage, they cancel out and you roll a single D20.
Can I use an online dice roller for D&D?
Yes. Most dungeon masters and players accept virtual dice rollers. The results are statistically equivalent to physical dice, and the speed of rolling multiple dice at once keeps the game moving.
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