Game Breaking?

[unglitteringold]

What sort of "stress tests" do you recommend for beta testing a system?
I want to try and find the holes in combat before I start running anything.

[Wyntonian]

Honestly, the best thing to do is post it to a forum like this one, dump chum in the waters and wait for the great schools of grognard-sharks to tear it apart. Getting a fresh set of eyes and seeing what a bunch of experts in this sort of thing can do with it is probably the most thorough way to test it.

[Amechra]

Playtesting.

• Once with you as the DM
• Once with you as a player
• Once without you playing the game, but on hand to explain stuff
• Once without you being around to help

Ideally you do the above a couple of times, each with different groups.

[Day_Dreamer]

Depends a lot on how your mechanics are structured, and what exactly you mean by "game breaking." Also, what expectations you have for combat.

If combat is supposed to be an engaging tactical game with a lot of choices, any "one true builds" are game breaking. D&D or Exalted are good examples of systems where balance is pretty important, and the game can be "ruined" (for some value thereof, anyway. I mean, people love both systems despite being full of game breaking builds.) if a power of combination of powers is too strong.
If combat is supposed to be just one part of a larger story, like Eclipse phase or some WoD games, then having absurdly overpowered–on paper–builds isn't that big a deal, as long as a single player can't be amazing at everything. Someone who wants to be the combat guy should be stronger at it then someone who wants to be the lore guy, after all. The issue is if there are ways to be too effective in combat, to the point where other people can't even contribute or compete.

Finding game breaking builds isn't that hard, at least for the really obvious ones. Think of ways that you can be really, really effective in the combat engine. What's the maximum you could conceivably get with your attack pool, or damage, or defense pool? Is the game configured such that someone who maxes one of those becomes unstoppable or unassailable? Can somebody get an attack that's near impossible to block, or that targets some weird subsystem that people aren't likely to have defenses for? Can somebody become invulnerable to most types of attacks? Can somebody figure out how chain stuns in a neverending combo, or Stealth so well that nobody else can possibly see them?

Big questions like that should be reasonably easy to answer, unless your system is really complicated.

Crowdsourcing feedback, especially from new eyes who are going to think about possible combos for the first time, is also valuable. I'm actually trying to do that right now, with my own system, and its been super useful so far.

Best of luck!

[UrielAwakened]

Find great optimizers and let them play it.

[avr]

Check that the game's combat fits the theme you want. e.g. If ranged combat is supposed to be more common than melee in the setting of your game (or vice versa) it's worth checking that the systems and the numbers support that. If your game wants to have werewolves duking it out with their claws, but a wall of gunfire kills werewolves before they get close that's a problem. If you want death from zombie infection to be an issue but any time the zombies score a big enough hit to infect then the target is likely dead already, that issue won't come up much. If you want Conan cleaving through mooks but it takes a minimum 2 hits to drop anything, that's not going to happen.

What sort of system is it?