BCG Retrospective V: The Core Mechanic

Today's Retrospective is all about Tests, the most fundamental rule in BCG. Tests are what we in tabletop design circles call the "Core Mechanic" of the game, which is to say, its method of conflict resolution. The rest of the system revolves around this mechanic, whether you are rolling dice, playing rock paper scissors, or playing cards. For example, BCG rolls 1d10 + Attribute vs a Difficulty Number set by the GM (usually between 1 and 20), modifying them by Advantages or Disadvantages. This is a mechanic that downplays randomness in favor of PC/GM control over success/failure probabilities, but leans towards making PCs succeed at tasks rather than fail.

It has a larger element of luck in its Core Mechanic than, say, 3d6+Attribute vs a static difficulty between 10 and 20, but smaller than rolling 1d100 under your own Skill Rating. The former system has 16 possible results (3-18) with a distribution leaning towards 10-11 (two 3s and one 4, or two 4s and one 3) which makes it easy to plan around, while in the latter system your odds of rolling a 01 are the exact same as those of rolling a 100, and there are 100 possible results instead of 15. The second mechanic is more random, and gives PCS and GMs less control over success and failure, because it is much harder to predict.

Advantages and Disadvantages are one of my favorite mechanics in BCG and I'm not embarrassed to say I'm proud of coming up with them. They do so much in a very simple yet effective way. The very first Advantage is better used to roll two dice than as a +2 bonus. After that you generally turn them into a +2 bonus unless you have something like an Unreliable Weapon where having a specific result is important. Most PCs can get from one to three Advantages to their Tests by spending XP towards a specialization or with competent tactical gameplay. Then they can go up to four or five Advantages by doing both things and jumping through a few hoops. This means it is very easy to roll between 10 and 15 at anything you care about and very hard but not impossible to hit 20 or go over it. Mecha Operations make the numbers go higher because of Genre Powers, but this idea holds up fine for Intermission Tests. Disadvantages are much rarer, because this is a game that wants the PCs to succeed more often than they fail, but when they do come up they make their presence felt because having your precious Advantages get cancelled out hurts.

The most common kinds of Tests in Intermissions are Skill Tests, and they're generally divided into four Difficulty Numbers: 5, 10, 15 and 20. The first, DN 5, is for relatively easy tasks that PCs can only fail with a combination of poor skill and terrible luck, thus they should only be rolled to highlight character flaws and possibly add some humor to the game. The bulk of the Skill Tests in the game should be of DN 10, which a PC with a moderate investment in Attributes (4-6) plus an Advantage or two has good odds of meeting, while more advanced PCs don't even need to roll for them, effectively being on a different level than other characters when it comes to their field of expertise. The Skill Tests of DN 15 should be the second most common, but still relatively rare, because they're a challenge aimed at characters trying to do something major in their field of expertise, it takes a considerable investment in Attributes, Skills and Traits (adding up to say 8-10 in an Attribute and two or three Advantages) or otherwise they will need outside help. The final and rarest DN is 20, which should only be used for those "I'm going to try and do something silly/awesome/stupid" moments in which the GM doesn't really expect a PC to succeed but can let them roll anyway.

It is an alright system, but kind of flat and just... Serviceable enough without any terrible flaws to it. The GM chapter includes some ideas for toying with these mechanics a bit and making them more interesting, which I would have integrated into the rules proper if Skill Tests were the focus of the game. But they aren't, the focus of the game is in its combat mechanics. The primary reason I went with this system was because it made Mecha combat math simple to design for and play with.

In Operations the most common kind of Test is, of course, Might Tests. The difference between the lowest, average, and highest result in any given attack roll is of about one Threshold Level between them - assuming an average Threshold of 4 or 5. So if you barely miss with a 1, then you do some decent damage with a 5 and considerable damage with a 10. Defenses start at 5, so you need a result of 6 or higher (assuming your Might equals the defender's Guard) to do any damage. In addition to Tension, you can get two Advantages fairly easily out of every Weapon other than the Default Ones, and three or more from Beam Weapons or those with drawbacks like Slow and One-Shot. By Power Level 2 defenders can get an easy 3 to 5 extra Defense from Active Defenses, which can be counteracted by high-end Weapons or stacked passive Advantages, like Artillery Frame + Sniper Model. Lastly, there's Genre Powers, some of which can be spammed every Turn of an Operation, while other can only be used once for each.

In general, the defensive abilities are stronger than the offensive ones (just compare Try Again to Not so Fast), but there's a greater variety of offensive abilities and they can be more easily combined while Defensive ones can't or have obvious weaknesses - Active Defenses can be pierced with Powers and Techniques can punch through Invincible Alloy. The most extreme defensive specialists can stonewall most attackers, but debuffs will flip them like turtles on their backs. It is a point-buy system, and the freedom that gives Players means some will try to make the most hyperspecialized builds. The game expects and welcomes ridiculous things like blowing up all enemies with a single Blast or being invincible if a PC does nothing but spam Maneuvers, but balances them with a number of hard counters. The game tends towards making everyone take at least a little bit of Damage every Turn, and at its most imbalanced (Usually during Power Levels 0 and 5) it feels a little too much like a game of rocket tag where people explode in one or two Turns of combat, but that's better than a game where people can easily make themselves impervious to most forms of attack and combat is a sleep-inducing slugfest.

I will concede that the math could have been tweaked a little bit more towards a middle ground and minimize instances of one-turn kills. For example, Defenses could have started at 10 rather than 5 and Threshold Levels could have been beefier (say, 2x Threshold each, instead of 1x Threshold), then defensive abilities would have probably been weaker and there would have been less ways to obscenely stack offensive buffs. We could have also made PC stats start at 5 rather than 0, thus saving all PCs from being disabled by harsh language automatically, reducing the XP given at character creation/each Power Level and overall keeping most of the math the same. That would have taken away from the freedom to make your character and mecha however you want though.

We could have also had more and better ways to restore Threshold, which I admit was a mistake in the core rules that didn't get fixed until the expansion. If that was too much, we could have put more Weapons that did bonus Damage to counter the healspam. The game would have been slower and would have needed a little bit more math with any of those changes, but the combat mechanics would have made a better use of the Tension rules, with more ways to temporarily increase it, use it as a damage bonus, or restore it after a Technique has spent it. It could have been interesting but, again, slower.

Ultimately I went with the options that made the game flow fast without sacrificing freedom of options. The current mechanics work well enough, but if I end up doing another combat-centric game, I'll be keeping in mind some of this stuff. If I don't then... Well, I'll probably explore more the mechanics I left as suggestions for Intermissions. I imagine you folks are more interested in flashy combat scenes, but do tell me if you're more interested in narrative and story progression mechanics.

Next time: All the Intermission Rules. Yes, all of them.

Gimmick Out.