About Face: thoughts on who rolls the dice

One recent Thursday we were trying out a new system. There was some confusion as to whether both the players and the game master rolled or just the players. Rolfe referred to only the players rolling as ‘player facing’. I had never heard that term before, but it does seem to accurately describe mechanics were only the players roll dice. This got me thinking about player facing mechanics and what they mean for a game.

The world does revolve around them

The most common mechanic seen in games is to treat player characters and non-player characters using the same mechanics. For example, in the grand daddy of them all D&D if a player wants to hit someone with a sword they roll their attack to see if they hit, and then damage if they do. If an NPC wants to hit a player then the GM rolls their attack and, if they hit, rolls damage, just like a PC. In contrast, in games like ICONS only the players roll. If a player attacks someone they roll to hit. If an NPC attacks a player there is no roll to hit, the player rolls to avoid the attack.

There are a number of advantages to a player facing mechanic. It makes less work for the GM. Rolling dice can be fun but is time consuming. Putting the mechanics onto the players, who usually outnumber the GM, can make things faster and easier for the GM. It also emphasizes that the game is about the player’s characters, they hit the opponent, they avoid the attack, they sneak past the guard, they notice the person trying to sneak past them, etc. The mechanics can also be very biased. If the standard roll succeeds 80% of the time then whoever rolled would have a big advantage. In a player facing system this would always be the players and so the bias would always work in the same direction making it easier to understand the likely outcomes.

There are also potential problems with a player facing mechanic. Some people just like rolling dice and the GM may miss this experience. Some people may not like the aesthetic of the player focus, say, feeling that it breaks immersion to not use the same rules for everyone. One game mechanical drawback is that there are no rules for NPC’s interacting with anything other than the PC’s. If the villain is trying to leap across a chasm there wouldn’t be any rules for rolling to see if the villain made it across. The GM then has to just decide whether the leap works or break the player facing set up. Breaking the player facing would require using the PC mechanics or making up a mechanic if the PC mechanics are completely inappropriate for an NPC. For example, the player mechanic uses a statistic that doesn’t exist for NPC’s. While many GM’s are comfortable just deciding some really like the results to be uncertain.

GM facing

Just as a game can be designed so that only the players roll it could also be organized so that only the GM rolls. It should be noted that this is not the same as games with no randomization, often referred to as diceless. A GM facing mechanic would still use dice, or cards etc, but only the GM would roll. The only published system I’m familiar with that uses GM facing is Everway. The GM draws cards to help determine the success or failure of actions.

GM facing mechanics could be great for introducing people to roleplaying. New players could concentrate on playing the character and choosing interesting actions rather than which dice to roll and which numbers to add from the character sheet. It would also be good for keeping information from the players. This is usually a bad idea but some genres really need limited information. A friend of mine used to run horror games using D&D rules. One of the changes he made was the he kept track of the character’s hit points. After all, it is pretty difficult to make someone worry about their character when they know that being hit ten times with a sword isn’t going to kill them.

A GM facing system has a number of potential problems. Putting all the work on the GM could be overwhelming or slow down the game as one person has to do all the rolling and math. Also, some players really hate not making their own rolls. The horror GM mentioned previously wanted to keep the rolls secret to keep things uncertain. His players out and out rebelled. So he had to let them make a large number of rolls ahead of time and then use them during the game. It might also be very unsatisfying for players that like the table top miniature aspects of role playing games.

Face painting

While most systems are built with both players and GM using the same mechanics all it would take is a few tweaks and many could be turned into a player facing system. For example, D&D could be made player facing. The standard mechanic for attacking a PC is rolling a d20 and adding the NPC’s attack bonus. If the total equals or exceeds the PC’s armor class (AC) then the attack hits and damage is rolled. So if the PC had AC 20 an opponent with a +9 would need to roll an 11-20 to hit them, a 50% chance. An opponent with +4 would need to roll a 16-20, a 25% chance.

Mathematically adding a d20 to the attack bonus is identical to the player rolling a d20 and subtracting the roll from their armor class. If the total is equal or less than the attack bonus the PC would be hit. So an AC of 20 against an attack bonus of +9 would require the player to roll an 11-20 to be hit, 20 – 11= 9, or a 50% chance. Against a bonus of +4 the player would need to roll a 16-20 to be hit, 20 – 16=4, or a 25% chance.

Of course, most people hate doing subtraction and would much rather add the die roll. To change the mechanic from rolling a d20 and subtracting from the AC to rolling a d20 and adding it to the PC’s armor class all you need is to add 22 to the NPC’s attack bonus. A +4 bonus becomes a 26, a +9 a 31. In order to be missed the PC would need to roll those numbers or better on their AC plus d20. For a 20 AC the PC would be hit if they rolled 1-5 or 1-10 respectively, or a 25% or 50% chance, just like the original mechanic.

Where does the 22 come from? The average roll on a d20 is 10.5. Going from subtracting a d20 to adding a d20 the total goes from subtracting 10.5 on average to adding 10.5 on average. Thus the average roll will increase by 10.5 + 10.5 or 21. So what about the extra 1? The original mechanic has the player being hit if the totals are equal. However, instead of having the player hit if they roll the target number or lower it is more consistent to have them missed if they roll the target number or higher, shifting the number by 1.
Saving throws would work just the same as attacks. Instead of the NPC rolling to save against the effect the player would roll to overcome the NPC’s resistance. The player would roll d20 and add it to the save number, for example a 14 for a mild poison. Just like to hit modifiers the NPC would have their save bonus plus 22, so a +4 fortitude save becomes a 26. If the player rolled equal to or better than the defense the effect would work. So in this example rolling a 12 or better, plus 14 for a 26 or better, would cause the NPC to be poisoned.

Rolling skills against each other would be similar. The present method is to roll a player’s skill, say spot, plus a d20 against the NPC’s skill, say stealth, plus a d20. This is mathematically equivalent of the player rolling a d20 and adding it to their skill and a d20 and subtracting it from their skill and then comparing to the NPC’s skill. Just like with hitting, this can be converted solely into addition. The player rolls 2d20 and adds the total to their skill and then compares it to the NPC’s. In this case, since ties are treated as ties, the NPC’s skill would only be adjusted by 21, so a +7 stealth would become a 28.

Final thoughts

What do you think about systems were only the players or the GM roll? Like it? Hate it? Indifferent? Are there any advantages or drawbacks to these systems that I haven’t thought of?