Star Trek Adventures: Developers’ Blog 002

By Nathan Dowdell, 2d20 System Developer

Basic Rules: Core Mechanics

The universe of Star Trek is one where bold Starfleet officers (or mighty Klingon warriors) often face—and overcome—challenging situations. Star Trek Adventures is built to present these kinds of situations for your player characters to solve.

In game terms, these situations normally involve tasks. A task is an activity where the outcome is uncertain. Player characters are expected to be competent, capable people who can solve most problems given time, concentration, and the right tools, but tasks normally occur in situations where characters don’t have enough time, where they lack the ability to concentrate, where they lack the tools, or where there’s some other factor which makes the activity uncertain.

Most of the time, you’ll simply describe what you want to do, and the gamemaster will determine whether or not you succeed. If there’s any doubt as to what would happen, the gamemaster will ask for a task.

When you attempt a task, you use one of your attributes and one of your disciplines. The gamemaster may let you choose which ones to use, or they may choose them for you, but either way, add the scores of the chosen attribute and discipline together: this is your target number. The gamemaster will also choose and tell you the Difficulty of the task.

Next, you roll two twenty-sided dice. Each die that rolls equal to or under your target number counts as a success. Each die that rolls a 1 counts as two successes, but if you have a focus which applies to the task, then any die that rolls equal to or under the discipline you’re using is worth two successes instead.

Total up the successes you’ve rolled; if you get fewer successes than the Difficulty, you’ve failed the task, and the gamemaster describes what happens next. If you got successes equal to or greater than the Difficulty, you succeed and the gamemaster describes how you accomplish what you were trying to do.

Getting more successes than the Difficulty means you generate Momentum. We’ll discuss the possibilities that Momentum provides in a later article, but for now: you can spend Momentum to improve the outcome of your success, such as getting more information from a tricorder scan or inflicting more Stress with an attack.

Lastly, if you rolled a 20 on any of your dice, you suffer a complication for each 20 rolled. Complications are extra problems that arise during a task, though a complication never results in failing at a task: if you succeeded and rolled a complication, you still succeed, but the complication happens as well. Complications, and Threat, which is a related matter, are discussed in more detail in a later article.


When the gamemaster sets the Difficulty of a task, it will normally be a number from 0 to 5. As will be explained in the article on Traits, the situation can alter the Difficulty of a task, so a task can become easier or more difficult if the circumstances change.

  • A Difficulty 0 task is immediately successful, and you don’t even need to pick up the dice. The gamemaster may still ask you to roll if it matters how well you succeed.
  • A Difficulty 1 task is a modest challenge, easy enough to overcome, especially if you’re skilled in that kind of task.
  • A Difficulty 2 task is a more challenging undertaking, and while possible for skilled characters to succeed reasonably often… characters may want to improve their odds of success.
  • Difficulty 3 tasks are very difficult, and characters must either trust to luck, get help, or otherwise improve the odds to succeed.
  • Difficulty 4 tasks are nearly impossible, and even the most skilled characters have only a very small chance of success without doing something to improve the odds.
  • Difficulty 5 tasks, and tasks with a Difficulty higher than 5, are actually impossible to succeed at if you’re rolling two dice, as you can’t generate more than four successes, even if you roll two 1s. You must improve the odds to have any hope of success.

Improving the Odds

We’ve mentioned “improving the odds” a few times, and this is really a key point of the basic rules: no matter what situation you’re facing, there is a way to make success more likely. Before you roll the dice, you can get assistance from another character present in the scene, or you can buy additional dice to roll on the test (more dice means more chances to score successes), or both.

  • Assistance means another character helps you. They roll 1d20 against a target number of their own (they use their own attributes and disciplines, which don’t have to be the same ones you’re using), and any successes they score get added to your total, so long as you score at least one success yourself… but you both suffer any complications that either of you roll. The gamemaster might place some conditions on assistance, such as an increased risk of complications, a maximum number of assistants, or limiting what an assistant can do in a scene while they’re busy helping you. A player character’s starship might even be able to assist with tasks as well, though we’ll discuss how a starship can assist you in a future article.
  • Buying extra dice is always an option. You can buy up to three extra d20s (for a maximum of five in total, including the two you started with) in a few different ways. If you’ve got Momentum saved up, you can spend some of that to buy dice: one Momentum for the first extra die, two for the second, and three for the third. If you’re more of a risk-taker, you can give the gamemaster some Threat to spend in exchange for extra dice (again, 1 for the first, 2 for the second, 3 for the third). You might have a talent which gives you a free extra dice in some specific circumstances. Most powerfully, if you spend a point of Determination before the roll, you can buy an extra die and it already counts as having rolled a 1, so you immediately get the best possible result.

Starfleet officers and Klingon warriors alike can always secure a good chance of success if they’re willing to work for it, using Momentum from previous triumphs, assistance from allies and comrades, or even taking calculated risks by adding to Threat, to give them the edge they need to overcome even the most challenging situations. 

Thanks for reading this article, and thank you for your interest and support of Star Trek Adventures! Keep your frequencies open for additional STA development blogs on a wide variety of game-related topics in the coming months.

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