Cold Take #39 - Special Abilities

A conflict has been brewing over the course of this series. Half the cold takes, those on general design principles, often imply that Zero-K avoids special abilities, while the other half shatter this impression by being about specific special abilities. In this post we will try to resolve this apparent disagreement by exploring how special abilities work and what makes an ability suitable for Zero-K.

The set of design principles arrayed against special abilities is truly daunting. To start with, abilities that require frenetic or precise clicks are rejected by the idea that players should not have to fight the UI. Many other potential abilities are ruled out for being too numbery, making units too stupid, or for imposing arbitrary target restrictions. Atomic unit design pushes us towards having few abilities, special or otherwise. But despite all these restrictions, Zero-K has many more special abilities than other games with Total Annihilation ancestry.

Some design principles encourage special abilities. Quant's Rule reflects a desire for units to be unique and interesting, and special abilities are certainly a way to achieve that. More importantly, special abilities are fun, and not just to use. Zero-K steadily accumulates special abilities as a result of its open source laissez-faire development style, with many contributors working on whatever they find most interesting. This process predates Complete Annihilation, as early engine developers added features such as bubble shields and the deformable terrain that makes terraform possible.

The pace of special ability development ramped up with the advent of Complete Annihilation and Lua scripting. Many of our design principles were also being hammered out around this time, but the purpose of them was more to channel this outpouring of creativity, rather than attempt to stem the tide. This period gave us area cloakers, morphing, jumpjets, terraform, and a host of manually fired weapon-like abilities. It is hard to overstate how satisfying it is to mess around with new abilities, I have even written abilities that my designer side knew had little chance of making it into the game.

In fact, the design principles that seem to restrict special ability design actually let it flourish. We were free to experiment within the guidelines without worrying too much about whether the result would be fundamentally at odds with the rest of the game. Our experiments could still fail, but less catastrophically; the game would not break. Without any guidance we may have been too scared, or disorganised, to try anything new.

So Zero-K allows, and even encourages, special abilities as long as they fit into the design. In practise this means abilities have to pass two tests: they need to make sense within the game world and they should not be too hard to use. Whether an ability makes sense is the easier of the two to judge, since we have reasonably clear rules about things like armour classes, and the "theoretical ideal ability" test from Aim and Fire can be used for more than weaponry. How hard an ability is to use, i.e. how fiddly it is, can be harder to judge, since it involves tradeoffs against how much the ability adds to the game. The two guiding principles for fiddliness are that players should not fight the UI, and that abilities should avoid making units implicitly stupid. A lot of fiddliness comes down to how much attention is required to use it.

The least fiddly type of ability is the passive ability. Damage types such as