13th Age: dice & strategy guide

13th Age, by Rob Heinsoo and Jonathan Tweet, is a d20 fantasy game that keeps what worked about the d20 tradition while stripping out the fiddly grid tactics. If you know how to roll to hit and beat a target, you already know most of it — the fresh ideas are what surround that roll.

The dice and the core mechanic

13th Age uses the full polyhedral set — d4 through d20 plus the d100 — but the d20 is the heart of every check. To attempt almost anything you roll:

d20 + level + ability modifier + any relevant bonuses, compared against a target number (usually called a DC for skill checks, or an enemy’s defence for attacks). Notably, your full level is added to nearly every d20 roll, so characters grow reliably more capable as they advance rather than only in their specialities.

How a roll resolves

Roll the d20, add your bonuses, and meet or beat the target. For attacks you compare the total to the target’s Armour Class, Physical Defence or Mental Defence; for a skill check, the GM sets a DC by tier of difficulty. A natural 20 is a critical hit that doubles damage; a natural 1 is a fumble. So far, so familiar — but two systems make 13th Age feel like itself.

The escalation die. This is the game’s signature. At the start of the second round of a battle, the GM places a d6 showing 1 on the table; each following round it ticks up, to a maximum of 6. Its current value is added to every player’s attack roll (monsters generally don’t benefit). Fights therefore start uncertain and swing towards the heroes the longer they last, punishing turtling and rewarding decisive engagement.

Icon relationships. During character creation you take a few points of relationship with the setting’s Icons — its great powers, such as the Emperor or the Diabolist — rating each as positive, conflicted or negative. At the start of a session (or when the GM calls for it), you roll one d6 per relationship point. A 6 is a strong, uncomplicated advantage; a 5 is an advantage that also brings a complication. These rolls seed plot, favours and trouble rather than combat bonuses.

Effective strategy

Lean into the escalation die. Because it only grows, dragging a fight out with cautious play hands the advantage to your enemies early and yourselves late — but the die makes late-battle player attacks brutal. Open aggressively to survive the low-escalation rounds, then let the mounting bonus close it out. Some monster and spell effects consume the escalation die; time those for when it is high.

Remember level is always added. Even outside your best skills, your level keeps you relevant. Don’t assume a check is hopeless just because it is off-speciality — the flat level bonus does a lot of quiet work.

Play your icon dice as story fuel. A 5 or 6 is an invitation. Tell the GM how that Prince’s favour or that Lich King’s grudge shows up this session; engaged players who narrate their results get far more mileage than those who roll and forget.

Use backgrounds, not a skill list. 13th Age replaces a skill list with freeform backgrounds. Frame what you attempt so a high background applies, and describe the fiction that justifies it.

Since the core is a plain d20 plus a d6 escalation die, you can roll a d20 and a d6 together in your browser and track the escalation with them.

Beginner tips & common mistakes

• Add your level to the d20. It is easy to forget on skill checks; it applies almost everywhere.
• The escalation die starts in round 2, not round 1. Round one has no bonus — plan your opening accordingly.
• Monsters usually don’t get the escalation die. It is a heroes’ advantage; check a creature’s stat block for the rare exceptions.
• Roll icon relationships and then use them. Sitting on a 6 all session wastes the mechanic’s whole point.
• Don’t treat it as a tactical grid game. Positioning is abstract; describing intent matters more than counting squares.

Curious how a stripped-back, difficulty-first d20 game compares? Read our Numenera & Cypher System guide.