Tokens are kind of currency that SGS uses to make the game more exciting and allow characters to perform actions that they wouldn't normally be able to accomplish.
You can spend 1 token to apply a +2 bonus to the roll of yourself or another entity or object by invoking one of its aspects. The invoke must make sense in the fiction: you can't invoke your motorcycle's speed in a college entrance exam, for example. Additionally, you can only invoke a given aspect once per check or roll.
You can spend 1 token to apply a -2 penalty to another character or object by binding one of their aspects. The bind must make sense in the fiction: you can't bind someone's colorblindness to apply a -2 to their athletics check, for example. Additionally, you can only bind a given aspect once per check or roll.
You can spend 1 token to force another entity to act within the bounds of one of its aspects, or a situation aspect in the scene. When you do so, you give that token to the owner of the entity. In the case of PCs, that means the PC's player. In the case of NPCs, that means the GM. In the case of objects, that usually means the GM, unless a PC owns or controls that object.
🔭 Double Range
You can spend 1 token to use an item at double the stated range, so long as it makes sense in the fiction and any rules the object might follow are observed. You can't use double range to shoot around corners, for example.
⚡ Extra Action
You can spend 2 tokens to make an extra action on your turn. That action can be any normal action that you could attempt during the scene. You can only take 1 extra action per turn.
🩸 Limit Break
You can spend 1 token to ignore all your damage penalties for one roll.
💨 Double Move
You can spend 1 token to make an extra movement on your turn. You may only do this once per turn.
🛡️ Reduce Damage
You can spend 1 token to reduce the level of damage you take from an attack by 1 step, to a minimum of 1. You may only do this once per attack, and you cannot reduce the damage past 1.
⚔️ Increase Damage
You can spend 1 token to increase the level of damage you inflict on an attack by 1 step. You may only do this once per attack. If you use this when you've already achieved the highest damage threshold, the target is knocked out.
You can spend 1 token to roll two dice instead of one, and take the higher of the two. You may only roll 2 dice per roll, ie you can't stack advantage.
🍀 Beginner's Luck
You can spend 1 token to roll 1d4 when you would otherwise roll no dice.
NOT Using Tokens
Some aspects are considered "autobound," which is to say that nobody needs to pay anything for them to be applied, instead they are always applied whenever they are relevant. Note: There may also be situations where there are autobind bonuses, not just penalties, but usually these are just handled as temporary bonuses given my the GM for particular situational advantages.
An example might be a broken leg. That broken leg aspect is going to apply a -2 pentalty to any kind of athletics, acrobatics, or movement-related skill rolls. Nobody needs to pay a token to bind it.
You cannot use a token earned by a failed roll to modify that roll. If you have no tokens when you make a roll, you can't apply any token-based modifiers to it.