Dialog flows and skill checks in Spy DNA

by Alex Maier, conversationist

Over the past few weeks, we focused a lot on combat in our game, but there’s another aspect to it: dialog. In Spy DNA you can talk to members of your party as well as NPCs, both at the base and during missions. While some missions have combat at their heart, others can be completed, or at least aided, by talking to people.

In the full release, you’ll be able to complement your Commander’s skills and attributes with those from your party. If the character you create lacks in stealth, charm, or ability to hit targets with any weapon, one of the nine specialist PCs can fill the skill gap and help you succeed.

In the Demo release, we’ll be including a few mission scenarios, and a limited complement of PCs to accompany you. Because of this, my goal as writer/level designer is to provide you with many different options to complete the missions where the combat-oriented PCs can’t help, to make any kind of Commander specialization viable.

Right now, I’m working on a covert mission where you’ll encounter only civilians, and if you screw up badly enough, civilian law enforcement. You’ll be under strict orders not to engage any civilians, and will fail the mission if you do. This means that you’ll have to use radically different tactics here than you would say, on the mission to extract the hostage from a remote rebel camp.

If you can’t shoot’em… talk to them, I guess?

If you can’t shoot’em… talk to them, I guess?

If your Commander is an infiltration specialist, you’ll have no problem convincing the people you speak with that you’re just an employee of the company you’re infiltrating. The security guards will let you stay and complete your task in peace.

But what if your Commander is more of a breach-and-clear kind of person? This is where level design becomes interesting. To provide a combat-oriented Commander with a viable approach, I’m including options to intimidate your vis-a-vis, if you couldn’t charm your way out of a wet paper bag. In addition to tough talk, your attire will also be taken into account, as will your other choices, which I don’t want to reveal quite yet.

To account for all the possible combinations of Commander abilities and under which circumstances they engage the person in the conversation, the dialog is very branched, and can have a variety of outcomes for the player. Here’s an example of a mostly finished dialog with a security guard in the building. It’s about 80 percent complete, so just imagine another branch or two in there.

Dialog tree example for an NPC on a generated mission

Dialog tree example for an NPC on a generated mission

Other NPCs in the level will have similarly complex dialog trees, and in each case, I’m aiming to provide options for a combat-oriented character to have a chance of success. Mind you, this will not be a requirement for generated missions in the full release, since you’ll have a full complement of specialist PCs in your squad, to help you get through the missions that your Commander wasn’t designed for.

While failing or skipping a generated mission isn’t going to endanger your overall objective of saving the world (as one does), storyline missions will have to include solution options for Commanders of all kinds. They may not be the most obvious ones, and may require a bit of planning ahead, but I’m determined to make sure y’all don’t get stuck because of choices you made during character creation.

Skill checks

As you’d expect, picking different dialog options and interacting with objects in the world results in a skill check which in turn decides whether you fail or succeed. You’d be “rolling” against the skill relevant to your selection (infiltration, intimidation, lockpicking, etc), but we also factor in an attribute, which gives you a chance to succeed if your skill is zero. The flip side to this is that an extremely poor attribute will generate a penalty.

The skill roll is also modified by Sigma, to set how steep the success/fail curve is. The smaller the sigma, the smaller is your margin from the number you’re rolling against. This means that you’ll experience a critical failure or a critical success with sigma of five more often than with sigma of twenty. Smaller sigmas are reserved for more daring checks, such as last-ditch attempts to convince that night guard that you’re not breaking in.

X axis represents difference between your skill and the difficulty of the task

X axis represents difference between your skill and the difficulty of the task

In the dialog example above, you’ll be checked against combinations of infiltration + leadership, infiltration + charm, intimidation + strength, or persuasion + mental quickness, to name a few. I select the attribute according to dialog context and common sense, to create the closest approximation to real life we can within our system.

While making your choices, you’ll usually have more than one attempt at succeeding within the dialog branch that you chose, but the guard will remember your choices, and you won’t be able to just quit the dialog and attempt a “redo” a moment later. That’s not how life works.

And on that cheery note, let me wrap up here and go back to writing those dialogs, instead of blog posts. Post your questions below or tweet at us, we’re happy to explain stuff in more detail if you’re interested!