What a system prompt does
The system prompt tells Claude who it is (role), how it should respond (tone, format) and which rules apply. It is the basis for consistent, role-based answers.
System prompt vs. user prompt
The system prompt applies to the whole chat. The user prompt is a single request. A good system prompt makes individual prompts more effective.
Skills as system prompts
Every ClaudePowerSkill is essentially a structured system prompt with role, workflow and quality rules. You do not need to write a system prompt yourself: the skill takes care of it.
Frequently asked questions
Do I need Claude Pro for system prompts?
System prompts are available in Claude Pro through Projects. In Claude Free you can set them manually as the first message.
How long should a system prompt be?
Short enough to be clear, long enough to contain all rules. Typically 100-500 words.