TTRPGs require two things to play: the game master (GM), and the players. The GM writes and simulates an impartial fictional world for the players to interact with. All great campaigns have a story, and it's the GM's job to gently guide the players in the direction of a story without breaking the rules or removing player agency. It's the players job, on the other hand, to respect the GM, the tone, the genre, and the story. They become characters in the world and make decisions as those characters.
TTRPGs are commonly divided into two sections: exploration and combat. Exploration is the phase of gameplay in which players are free to explore and interact with the world. Exploration boils down to the following gameplay loop:
It doesn't have to follow this exactly. The point is that the GM simulates the world and the players make choices in it with an element of realism and chance based off their characters. Combat is a unique phase of gameplay in which groups of characters battle using a more structured set of rules.
Dice rolls in TTE use the following polyhedral dice (and a coin): d2, d4, d6, d8, d10, d12, and most importantly, the d20. The d2 has two sides, and the d4 has four, etc.
Whenever a character attempts to perform an action that has a significant chance of failure, the GM can call for a skill check. Skill checks use one of the 18 core skills or a custom skill. The character rolls 1d20, adds their level in the associated skill, and adds the core stat that skill inherits from. For example, if a player is attempting to chop down a tree, the GM could call for an athletics check. The roll would be 1d20 + Athletics Level + Strength. Then, the GM sets a difficulty for the check (commonly abbreviated to DC). These typically range from 1-30, where 1 is almost impossible to fail, and 30 is nigh impossible.
No matter your skills or stats, there's always a chance for success and failure while making skill checks. If you roll a natural 1 (referred to as a nat 1) on the d20, you will always do as poorly as you possibly can. Contrarily, if you roll a natural 20 (referred to as a nat 20) on the d20, you will do as well as you possibly can. Even if you roll a nat 20, you cannot perform an impossible action.
You can also have Advantage or Disadvantage on a roll. Advantage lets you roll twice and keep the higher roll, and disadvantage makes you roll twice and keep the lower roll. Advantage and disadvantage can come from the GM if the context demands it, or as part of your character.
EXAMPLE
GM: You walk into a bustling tavern and see a strange hooded figure in the back playing with some coins. What do you do?
Player: I'd like to look around for any clues about who he might be.
GM: Give me an investigation check
Player: (rolls a 16, with a WIS of 2, and an investigation skill of 1) I got a 19
GM: Your eyes dart around and you quickly take note of several armed men who are each paying close attention to the hooded man. Your instincts tell you he may be worth something to them; maybe he's got a bounty on his head.
Combat starts whenever 2 or more individuals of opposing sides attempt to use a weapon or intentionally cause damage to one another. The GM can also choose to initiate combat.
The first step of combat is to break into teams. In most scenarios, this will mean the players vs the enemies. However, more nuanced situations can arise with 3 or more competing teams.
To determine the order of turns, each team rolls 1d20. Teams then take their turns in descending order from highest roll to lowest. Each round of turns lasts roughly 6 seconds in real time.
On a team's turn, members coordinate what they'd like to do. Each member can make:
The team's decisions resolve simultaneously.
Actions are the backbone of combat. You can use your action to:
You can move once per turn without expending your action.
Bonus actions are, by default, unused. Your character may gain bonus action options depending on acquired abilities.
Free actions are for minor activities that don't require a roll or significantly impact the situation. Examples include:
Attack rolls are skill checks made to determine whether you land a hit.
When a player (not an NPC) is reduced to 0 HP or lower, they begin dying.
Each turn thereafter, the player and the GM privately roll 1d20:
NPCs reduced to 0 HP or lower die immediately without making death rolls.