Cypher Limit
You can only have a small number of cyphers at a time, called your cypher limit (for most characters, the limit is two). The game does this to encourage you (the player) to use cyphers instead of hoarding them for an emergency.
Your type tells you how many cyphers you can have at a time. Some focus abilities and abilities at higher tiers increase your cypher limit.
When you create a new character and join a campaign, the GM should give you enough cyphers to put you at your cypher limit—"fill you up" or "top you off" with cyphers, as it were.
Gaining New Cyphers
Every time your character has a significant rest (such as making a one-hour recovery) is a good time for the GM to award you more cyphers. You can think of this as a break between two significant scenes in a story; the characters have rested, have moved to a new location, or are about to face a new challenge, and now you have new cyphers to make use of.
Recoveries, page (ref)
To simplify things, the GM might offer new cyphers to all characters at the same time, even if not everyone is resting. For example, if you're resting for an hour, your friend Sandy is searching the internet for a clue, and your friend Robin is standing guard, the GM could offer new cyphers to all three of you at the same time.
At any time, as your action you can "lose" (discard) one or more of your current cyphers. This frees up space (not actual space in your pockets) so you can "find" another cypher. For example, if you have a cypher that gets rid of a poison in your system and you don't think you're going to face any poisonous threats this session, you can lose that cypher and make room for a new one the GM is offering you. Of course, if your current cypher is immediately useful (like rallying a wound), you could use it (gaining its effect), which frees up a space for a new cypher.
It is likely that if you play a character for a while, you'll end up with a cypher you've had before, and that's totally fine. It's also okay if you end up with two of the same cypher at the same time, but if that happens you might want to discard one so you have more options.
Your GM might hand out cyphers randomly by rolling on one of the tables in this chapter or by drawing random cards from a deck of cyphers. Or they might plan ahead and choose what cyphers you find based on upcoming encounters—for example, a healing cypher if there's a dangerous creature up ahead or a swimming cypher because soon you'll have to cross a lake.
It's okay to let the GM know when you're out of cyphers or haven't been at your cypher limit for a while. Even the best GMs sometimes forget to check on your cyphers, and reminding them means they get the fun job of handing out new cyphers to the group. After all, seeing how players come up with unexpected and creative uses for their cyphers is one of the perks of being a GM!
The GM should have a general idea of what cyphers you have so they can create encounters that make those cyphers useful. It's not fun if you have a climbing cypher and no opportunity to climb something.
Sometimes the game rules talk about how many cyphers you are carrying. Saying "I have two cyphers" and "I'm carrying two cyphers" mean the same thing.