Simple Gambling Rules

Gambling Rules

(Adopted from Knave 2E)

I love the gambling rules that Ben Milton cooked up for Knave 2E. However, I wanted to give them just a little more depth. I’ve added rules for handling characters who are skilled at gambling (card sharps, riverboat gamblers, and the like) as well as cheating.

Basic Rules of Gambling

Know when to roll 'em...

The player wagers an amount of money (up to the house limit). The House (GM) rolls 1d6.

The player then decides to either bow out (losing half their wager) or try to roll 1d6 and beat the House’s roll.

If the player rolls and succeeds, they win an amount equal to their wager. If they roll equal to or less than the House’s roll, the player loses their wager.

Gambling Skill

A skilled gambler (based on a feat or similar mechanic) has a slightly better chance of beating the house. When rolling, the player rolls 1d4 in addition to the normal 1d6.

If either of these dice rolls are greater than the House’s roll, the player wins an amount equal to their wager.

Cheating (Optional)

The GM might consider letting a character cheat. A cheating character may re-roll their d6 immediately after rolling it (and comparing it to the House’s roll). A cheater may reroll once per wager.

However, if the re-roll exactly matches the House’s roll, the character has been caught cheating!

Note: You might allow a cheater a Saving Throw, Dexterity check, or similar means of evading detection once caught.

Probability

If my simple simulations are correct, player’s have about a 42% chance to win each wager (assuming they always roll against the House). These odds are similar to the odds of winning a hand of Blackjack.

Gambling skill improves a player’s chances of winning to about 48%. This feels about right for a professional gambler. Odds are still in the favor of the House, but not by much.

Cheating gives the player a 58% chance of winning each hand. However, they have a 16% chance of getting caught each time they cheat. Note that this isn’t completely accurate, as no one player would cheat if the House rolls a 6 (since the best they could hope for is getting caught). I’m not especially motivated to calculate the actual odds at this moment, but I might do so if I ever revisit and expand these rules.

Simple Encumbrance for OSR

I'm working on a set of simple encumbrance rules that can work with relative ease with any version of TSR D&D or D&D retro clone. The following system owes a great deal to a bunch of "slot-based" encumbrance systems that other designers have created. It's based primarily on Ben Milton's Knave and an idea I took from Kevin Crawford's Worlds Without Number. The version presented below was written specifically for Swords & Wizardry Complete Revised. If you're adapting it for a different version of D&D, you might get slightly different results depending on how your rules handle "to-hit bonuses" for Strength.

Item-Based Encumbrance

An adventurer can only carry a limited amount of equipment, weapons, and treasure before becoming weighted down. Rather than track the actual weight of the various pieces of gear a character is carrying, this system counts the total number of items and uses that to measure encumbrance.

For rules purposes, an item is an abstraction representing an object that could be easily carried in one hand, generally no longer than a common sword and no heavier than about 5-10 pounds. Heavier objects, two-handed weapons, or very bulky or awkward objects count as two items.

Small objects that are generally sold as a bundle (arrows, caltrops, torches, etc.) count as one item per bundle. Very small objects don’t count toward encumbrance except in extraordinary quantities. The clothing and jewelry a character is wearing doesn’t usually count toward encumbrance, but worn armor does.

Treasure also counts toward encumbrance. Treat every 1,000 coins or gems as 1 item (round down, so any bundle of fewer than 1,000 coins doesn’t count).

Maximum Items Carried

A character can carry 5 + “to-hit modifier” ready items and 10 + “to-hit modifier” stowed items.

Ready Items

Ready items represent equipment commonly carried in a character’s hands, on their belts, and in other easily accessible locations. These include armor worn, sheathed weapons, etc. A character can usually access a readied item without taking any extra time during a combat round. Each character can carry up to 5 readied items, plus or minus the “to-hit modifier” determined by their Strength.

Stowed Items

Stowed items are any items tucked away in backpacks, bundled and stored in sacks, and otherwise carried with an eye toward transportability over quick access. It takes at least one round to retrieve a stowed item (and could take longer at the GM’s discretion). A character can carry up to 10 stowed items, plus or minus their “to-hit modifier”. Although the system is somewhat abstract, the GM might require a player to declare where these items are stored: a backpack, a sack, etc.

Overburdened

A character who carries more than their maximum allotment of items becomes overburdened. An overburdened character suffers a -5 penalty to attack rolls, suffers a 2 point penalty to AC, and loses any Dexterity and shield bonus to AC. They generally cannot dodge traps and other hazards, automatically failing saving throws that require mobility.

GM Notes

Separating a character’s carried equipment into ready and stowed items gives the referee a number of options during play. A character who loses access to their backpack might also lose access to their stowed equipment. Getting blasted with a fireball might carry the possibility of damaging ready items. In a particularly chaotic combat, perhaps the player must roll under their Intelligence each round in order to retrieve a stowed item. 

Finally, remember that this system is intentionally abstract. Feel free to apply the effects of being overburdened to any character lugging a very heavy object (a large rock or an anvil for example), regardless of how many items he or she is carrying.

Analysis

The following breakdown illustrates how many items a character of a given Strength score can carry, both ready and stowed.

On Diseases in Orginal D&D

One small project I’m working on is writing out rules for handling disease in old school D&D. My general goal is to craft some mechanics that can work, with minor tweaking, for most any TSR era edition of D&D. Whenever possible, I want to use existing rules published by TSR. It’s not a hard requirement, and I’m willing to tweak any rules I find, but I’d at least like to start with something "official".

And I thought I was onto something, but now I don't think so at all. In doing some research on this, I found this post from Delta’s D&D Hot Spot, where he points out that the earliest rules for Diseases in D&D actually appear in OD&D supplement 2, Blackmoor.

Alas, despite Delta’s endorsement and his general enthusiasm, I don’t think these rules actually work. Let’s take a look at why.

The Effects of Being Sick

Here's a portion of the rules in question:

 

 

 

 

 

Fatality

The most straightforward effect of contracting a disease under this system is that doing so might kill your character. For each disease, Blackmoor gives a flat percentile chance that your character will die from having contracted it. Bubonic Plague, for example, has a 35% fatality rate.

What the rules don’t say, however, is when to roll for fatality. The only mention I can find related to this is the following: “Players may get cured by the local Magic User or Cleric but they must do so before the referee rolls for their death.” So, it’s important in this system to know when the fatality roll occurs, but there’s no indication when to do so.

Strength Decrease

The other effect of having a disease is that it weakens your character, literally reducing their Strength:

“During the early stages of the disease the player will lose the use of strength points based on the days they stay out of bed.”

I really like the idea of diseases decreasing your strength. However, here’s where things get a little clunky.

“… for a disease that lasts 1–5 days, each day they will lose 20% of their strength points.”

It took me a minute to figure this out, but what the rules are saying is that the GM should divide the total possible Strength damage out across the full duration of the disease. Not the duration rolled by GM, mind you, but the maximum potential duration. That’s why the example says 20%, because 20% across 5 days (the maximum duration for the example disease) adds up to 100%.

But wait, that’s not the whole picture. The rules go on to say:

“in ALL [sic] cases the percentage will be taken out of 18 strength points so 20% … [equals] three strength points (all fractions are ignored).”

If you’re confused, what the author* is saying here is that you don’t actually reduce the character’s STR by a percentage of their character’s Strength score, you reduce it by a percentage of Strength 18, which represents the maximum Strength a character can possess in OD&D.

And here’s my next annoyance with this system. If the amount of Strength a character loses from a disease is a percentage based on the disease’s maximum duration, and it’s always applied to 18…then that’s a static number. There's no reason to require the GM to math this out.

Take the example disease, which lasts 1-5 days. Let’s assume it’s cholera, since that matches the duration. The example tells us that cholera reduces the character’s Strength by 3 each day (20% of 18, rounded down). The frustrating thing is that the number here, 3 Strength, will never change for this disease. It’s always just 3. Instead of making the GM divide 18 by 5…JUST WRITE 3 ON THE TABLE.

The Math Doesn’t Actually Work

With the above in mind, I went through and did the math on all the listed diseases, thinking that would solve the problem. Alas, doing that just revealed a new issue. Before I explain, it’s important to remind the reader about a couple things from the rule that I quoted above: 

1. The author says a character will lose strength points based on the number of days they stay out of bed.

2. We're supposed to ignore fractions when we calculate the strength loss.

But what am I supposed to do with Dysentery, which lists a duration not of days, but of 1-4 weeks? Am I supposed to convert those weeks to days, so that a character loses Strength over 7 – 28 days? That doesn’t work, because following the math given in the example would mean a PC is supposed to lose 18 Strength spread across 28 days, or .64 points per day. But remember, the rules say to ignore factions (which would include decimals). So, uh, 0 Strength per day?

Maybe It’s Per Week?

Perhaps, even though the rules clearly say per day, the author meant per time unit (week, day, whatever). So Dysentery reduces Strength at a rate of 4 points per week. That checks out.

Until we consider Tuberculosis, which has a duration of 4 – 24 weeks. Now we’re talking 18 divided by 24 (if we use weeks) or 18 divided by 168 (if we use days). Either way, we're rounding to zero. Unless I’m utterly missing something, these rules don’t actually work for at least two of the diseases.

Strength Loss Doesn’t Mean Much Anyway

Even if I solve the problem above, let’s discuss what a temporary loss of Strength actually means. In OD&D as written, the answer is: basically nothing. If you’re playing a fighter, high Strength grants an XP bonus. It doesn't grant an attack bonus, a damage bonus, or do much anything else of note.

To be fair, though, Blackmoor came out after the Grayhawk supplement, which one could argue means it was meant to be used in conjunction with the expanded ability score rules:

 

 

 

 

So I guess it’s kind of important? I’m not totally angry at the idea of Strength damage for disease, but its effect really hinges on which version of old school D&D you're using.

The Disease Table Isn’t Consistent with the Other Rules

If you read the actual disease descriptions, you’ll also notice that they often contradict the stats written in the table. Looking at Bubonic Plague, for example, we can see that the % chance to catch the disease is 1%. That seems low for a disease that ravaged most of the population of Europe.

But, reading the full description of plague, it says “any person that contracts this disease will infect 90% of the people he comes in contact with.”

What the hell Blackmoor? I guess we’re meant to understand that a person has a 10% chance of getting the plague from fleas, but then a 90% chance to get it from a person who already has it. While I’m fairly confident with my interpretation here, I’m still annoyed at how awkwardly it reads.

There’s More

Honestly, these aren’t the only warts in this system that I’d need to iron out to actually use these rules. I’m not going to delve any deeper here, though, because it just isn’t worth it. While I may still use these rules as inspiration, I’m afraid I can’t do much with the mechanics. I'll dig around a bit more, but I'm not too confident that TSR gave me any rules for diseases that I can easily crib.

 

* D&D co-creator Dave Arneson is credited as the author of Blackmoor. However, there is some debate as to who wrote what part of Blackmoor, so I’ve chosen to be generic about my references to the author.