Roleplayer #23, May 1991

The Double-Blind Arena

Realistic One-on-One Combat

by Barry Link

The band of spacefarers had chased the villain through several star systems before tracking him down on an alien planet. But he was safe behind walls of stone, and stronger walls of force. His guards were powerful and well-armed. A pitched battle seemed inevitable. Sonic blades hummed; laser safeties clicked off. Then the 3-V clicked on and they saw their foe's smiling face, saying "Let's make this sporting. I'll release the hostages and return the secret documents to you on one condition – that your champion defeats my champion in single combat."

It's a classic storytelling situation. What heroic PC could resist the chance to single-handedly save the day – or die in the attempt? This gives the GM an excellent chance to introduce some real drama into the campaign.

Unfortunately, one-on-one combats in roleplaying games often don't match the potential of the moment. The reason is lack of imagination. The fights are too straight-forward, composed merely of a couple of guys hitting each other on a blank hex map. Two swordsmen face each other, and a few clangs later one is down. Two gunmen draw, and the resolution takes even less time and effort. The one-on-one doesn't have to be dull, however, and the Double-Blind Arena is one method of spicing it up.


The Double-Blind Arena works on the principle of the double-blind system of movement and line of sight (LOS), where neither player can see the other's position on the map unless the character pieces on the map can actually see each other. Double-blind mechanics have been used for years in unofficial variants of wargames like PanzerBlitz and Squad Leader. This is one of the best methods to introduce the fog of war into gaming. It can be incorporated into any GURPS world background or genre, be it fantasy, science fiction, or the American Old West.

In our arena, two combatants enter the playing area at opposite ends armed with identical starting weapons and armor. They seek out the enemy, collect extra weapons and equipment, and dodge traps and monsters. Neither champion may leave until one is down. The winner is the one left standing.


The group should have an Adversary player to play the villain's champion in combat. Otherwise, an impartial player must be a temporary GM to referee the Arena while the GM plays the role of the Adversary. This is necessary to preserve the play balance of the system.

You need three, full-size copies of a map like the Orcslayer cavern map (reproduced here). Give one to each champion and one to the GM. The maps given to the players are known as blind maps; the GM's map is the master map. Each map should have two figures to represent the two fighters. Place each player and his map so that he cannot see the map of the opposing player. The GM should be able to see both blind maps at once.

In addition, you need another arena map (a reduced photocopy is fine) which you can make notes on. Called the planning map, it is the GM's guide to the location of weapon and equipment caches, traps, and monsters. Before play begins, determine the map placement of each cache and the difficulty modifier for finding it with a Vision Roll, and record this information on the planning map. Do the same for any traps and monsters.

Choice of Champions and Outfitting

The adventurers can select anyone from their party to be their champion. The GM or Adversary does the same for the opponents. For dramatic purposes, the villain should not reveal his or her choice of champion until after the PCs select theirs. A nifty champion for the enemy side is an affronted Enemy from the party's past – the more surprise you can deliver, the better the flavor of the moment. "Count Schrecker the Razor? We thought we put you away for good . . . "

The champions are outfitted with identical weapons and armor. Neither contestant is allowed to take in their own weapons, equipment, magic, or high-tech devices. TL8+ body implants and modifications are exempt subject to the GM's ruling. The starting weapons should be simple and something that neither combatant has any special proficiency with. For example, give medieval melee weapons to high-tech characters. Starting personal armor should provide light to moderate protection.

Who's Around the Corner?

Initially, each player places only the figure representing his own character on the map. The player sees on the map only what his character can see. Line of sight is blocked by walls and affected by the varying light conditions. The GM is the final arbiter of what can and cannot be seen.

As the player moves his figure on the map, the GM updates the player about what exists in the character's field of vision, even in the middle of a move. If a character walks two yards around a corner and sees his opponent coming down the hall, he still has two or three yards to move out of the way. The GM also tells each player what they hear, smell and so on . . . clues can include explosions, footsteps, heavy breathing, etc.

When the opposing character comes into view of a player's character, then the GM places the new figurine on the second player's map. He removes it if the opposing character ceases to be in line of sight.

Important: The GM's messages to players should be sent by written note so that a player cannot eavesdrop on the information supplied to his opponent.

Observers and Cheating

The PC champion's friends will want to watch the combat, and it would be pretty dull if they couldn't. Observers in a fantasy campaign can watch through the use of magic (supplied by the villain if the adventurers lack it) or, in higher-tech worlds, on video monitors. In a genre that lacks both high-tech or magic – Swashbucklers for example – make the Arena a pit. The villain and the PCs thus watch from above.

Obviously, the enemy will have magical or high-tech protections against interference. And you as the GM will not want the champion's friends yelling, "Look to your left!" at a crucial moment. But, if the PCs want to slip their champion some discreet help, secretly casting a protective spell on him before he goes into the arena, or using psi to report the movements of the opposing champion, let them try! If they're caught by the villain, all the better!

The general rule: any help they give their friend is legal in the game, as long as it's done through game mechanics. Whether "honorable" PCs will cheat is entirely up to them. (And the enemy can be expected to cheat.)

Variable Lighting

Obviously, the less light there is, the harder time the champions will have. You can set the light at a permanent level at the beginning of the battle, or change it during the encounter. This forces the champions to adjust to a changing situation, when the dim lights fade to total darkness, and then five minutes later become near-blinding.

Traps and Monsters

Traps and that old standby, wandering monsters, will also keep the champions on edge. Traps should be non-lethal. Don't use floors that crumble into a pit of fixed spears. Traps should wound, or annoy, or both. A spike which pierces a limb is a good injurious trap; a floormat that sticks to a fighter's boot (-1 DX) is a good annoyance. The idea is to create tension, not to end the fight before the combatants see each other.

The same goes for monsters – they should not be overwhelming, but just nasty enough to give the players pause for concern. The GM directs the movement of monsters.

Weapon and Equipment Caches

As the fighters move through the arena, they search for hidden caches of equipment and weapons. As they near the secret locations of caches, the GM makes Vision rolls for them, with the difficulty modifier he has assigned to each cache.

If a roll is successful, the PC can open the cache. None are trapped – probably. Upon opening the cache, the player rolls 1d on the Cache Contents table. The result indicates either that he goes to another table or that the cache is empty.

Here are a sample Cache Contents Table and subtables designed using Ultra-Tech and a TL10 background.

Cache Contents Tables

Roll 1d for general cache type:

1 – Melee Weapon
2 – Missile Weapon
3 – Armor
4 – Drugs
5 – Miscellaneous
6 – Empty

Melee Weapon Table

1 – Vibroblade
2 – Stunwand
3 – Monowire whip
4 – Neurolash I
5 – Sonic blade
6 – Monowire blade

Missile Weapon Table (each carries 1d-3 shots, minimum of one shot)

1 – Sporting Pistol
2 – Holdout laser
3 – Needler
4 – Nerve Pistol
5 – Sonic Stinger
6 – Tangler pistol


1 – Monocrys light vest
2 – Reflec suit
3 – Chameleon cloak
4 – Distort belt
5 – Holobelt (GM chooses image)
6 – TL6 steel helmet


1 – Grenade (1-3 smoke, 4-6 tear gas)
2 – Emergency medkit
3 – Biphase rope (10 yds)
4 – Sniper mirror
5 – IR contacts
6 – Flashlight


1 – Adder (choose type randomly)
2 – Rage
3 – Shaker
4 – Superstim
5 – Tempo
6 – Analgine

Sample Arena

Illustrated below is a layout of a sample arena for a TL10 Space campaign. This is the planning map. The E's mark the two entrances where the champions start the battle. Each champion is armed initially with an ablative armor vest, a small TL10 BPC shield (PD 2, 4 lbs, $80), and a large knife.

At each C is a hidden cache, and beside it is the Vision Roll modifier for spotting the cache. The Cache Contents Tables are the ones described above. There are no traps in this arena, but there is a sqook (GURPS Humanx, p. 31) at each S. The lighting in the Arena is dim, giving a -3 penalty to Vision and combat rolls.

Expansion and Options

The arena can be any size or shape. You can add two or three cavern maps together, you can use one of the large battle maps SJG produces, or you can make up your own. With larger maps, you can also add more combatants. Three or four opposing fighters can be allowed, or even teams. As long as the GM can keep track of each character's movement and LOS fairly and quickly, anything goes!

After the Combat

What happens after the combat is up to the GM. If the PC champion loses, the PCs will have to think fast. If the villain loses, the adventurers must ensure he lives up to the bargain (he probably won't).

How the Double-Blind Arena fits into your campaign is up to you. It can be a logical and dramatic part of any cinematic story line. When the time is right, have the villain laugh gleefully and announce, "Let the contest begin!"

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