Mörk Borg: dice & strategy guide

Mörk Borg (Swedish for “dark fort”) is an award-winning, rules-light OSR game — a bleak apocalyptic fantasy famous as much for its screaming graphic design as for its brutal, elegant rules. You can learn the whole system in minutes; surviving it is another matter.

What dice Mörk Borg uses

Mörk Borg uses a full polyhedral set — d4, d6, d8, d10, d12 and d20, plus the percentile d100 for its many random tables. The d20 is the workhorse for tests, while the smaller dice handle damage, weapon and armour ratings, and the game’s abundant tables of scrolls, misery and horrible fates. Its four abilities are Agility, Presence, Strength and Toughness, each a small modifier from roughly −3 to +3.

How a roll resolves

There are two things to remember, and that is nearly the whole engine.

Ability tests use a d20, and you want to roll HIGH. Roll d20, add the relevant ability modifier, and meet or beat a DR (Difficulty Rating). The default DR is 12; the GM raises it for hard tasks and lowers it for easy ones. Roll a natural 20 and it is a critical success; a natural 1 is a fumble — often catastrophic.

Combat is quick and deadly. When you attack you make a DR 12 test; when a monster attacks you, you make a Defence test to avoid it — the player rolls, not the GM. A miss means you take the hit. Weapons and armour are rated by die size (a weapon might deal d6, armour might reduce damage by d2 or d4), and your total HP is famously low. Fights are resolved in a few rolls, and they can end a character in one bad exchange.

A note on editions: some tables raise abilities so tests roll d20 under a target instead of over a DR. Base Mörk Borg is the roll-over-DR system described here; a few of its many hacks use roll-under, so confirm which your table uses.

Effective strategy

Avoid the fair fight. With such thin HP and a flat d20, straight combat is a coin-flip that kills. Ambush, trap, bribe, flee, collapse a ceiling — the surviving parties are the ones who turn a battle into an execution or skip it entirely.

Hoard nothing — use everything. Silver, torches, food and the game’s unpredictable scrolls (its magic, drawn from Sacred and Unclean powers that can backfire on a bad roll) are scarce and often one-shot. In a world this grim, the item saved “for later” usually dies with you. Spend resources to survive the encounter in front of you.

Let the player-facing rolls work for you. Because you roll to defend, positioning to reduce the number of attacks — fighting in a doorway, keeping cover, retreating — directly cuts how many deadly dice you have to face.

Reward creativity over stats. Mörk Borg deliberately keeps modifiers small so that plans, not numbers, decide outcomes. A clever approach that lowers the DR (or removes the roll altogether) beats a big bonus.

Because it uses a plain polyhedral set, you can roll a d20 and the whole set in your browser and let the totals sort themselves out while you narrate the carnage.

Beginner tips & common mistakes

• Base tests roll high against a DR. The default DR is 12 — d20 plus ability, meet or beat it. Don’t assume it is a roll-under system unless your specific hack says so.
• You roll to defend. The GM doesn’t roll to hit you; you roll to avoid being hit. Forgetting this stalls combat.
• Expect to die — and prepare for it. Character creation is fast by design. Have a back-up concept ready and don’t over-invest emotionally in a level-one scavenger.
• Scrolls can bite back. Powers can fail or harm the caster on a poor roll. Read the risk before you unleash one in a tight spot.
• Cleverness is the real character sheet. Small modifiers mean the smart play — not the optimised build — is what keeps you alive.

Want another game where fragile characters and dread rule the table? Read our Call of Cthulhu dice & strategy guide.