Rolls (one troop always stays behind) (needs 2 troops to attack)
Rolls (territory is empty)
Each meter is the chance of winning from the position showing now, worked out exactly over every dice outcome, for a fight that runs to the end with the defender rolling .
Both sides lose a troop.
Territory taken after . The attacker has troops left, so up to can move in and at least 1 stays behind.
The defender holds after . The attacker is down to 1 troop and cannot attack again, and still standing.
Battle log
| Round | Attack | Defence | Losses | Left |
|---|---|---|---|---|
| / |
Risk dice roller
Two big stacks facing each other, and nobody wants to roll it out by hand. Put in the troops on each side, then fight to the end in one click or step through a few rounds at a time. Real Risk rules, real dice, plus the exact odds before you commit.
How a Risk battle is rolled
- 1 The attacker picks up dice. One die per troop past the one that has to stay behind, up to three. So 4 or more troops means 3 dice, 3 troops means 2 dice, 2 troops means 1 die, and 1 troop cannot attack at all.
- 2 The defender picks up one or two. Two dice with 2 or more troops, one die with a single troop. With 2 or more, the defender may still choose to roll just one.
- 3 Highest meets highest. Both sides sort their dice from high to low. The top pair is compared, then the second pair if both rolled at least two. Any extra attacking die has nothing to face, so it does nothing.
- 4 The loser of each pair loses a troop. The attacker has to roll strictly higher, so a tie goes to the defender. That is the whole reason defending is stronger than it looks.
- 5 Repeat until it is settled. The territory falls when the last defender is gone. The attack dies when the attacker is down to 1 troop, because that troop can never leave.
Questions
- How many dice does each side roll in Risk?
- The attacker rolls one die for each troop beyond the one that has to stay behind, up to three. So 4 or more troops means 3 dice, 3 troops means 2 dice, and 2 troops means 1 die. The defender rolls up to two dice, one for each troop they have, and may choose to roll only one.
- Who wins a tie in Risk?
- The defender. Each side sorts its dice from highest to lowest, then the highest attacking die is compared to the highest defending die, and so on. The attacker only wins a pair by rolling strictly higher, so equal numbers cost the attacker a troop.
- Should the defender roll one die or two?
- Rolling two is better in almost every position, because it lets the defender knock out two attacking troops in a single round. Rolling one caps the round at a single casualty, so it only makes sense when losing two defenders at once would cost you the territory. You can set either behaviour in this tool and compare the odds.
- Are the odds simulated or exact?
- Exact. The tool works through every possible dice outcome for every possible position in the battle, so the win chance and the expected survivors are the true numbers, not a sample from running the battle many times. The dice you roll are separate and genuinely random.
- Is the Risk dice roller free?
- Yes, completely free, with no sign-up. It runs entirely in your browser, so nothing you type is uploaded anywhere.
An unofficial fan tool. Risk is a trademark of Hasbro, who are not involved with this page. Made by Hamze Ammar. Roll well.