Gemini Prompt Cheat Sheet (2026): Formulas, Modifiers & Gems

Keep this page open while you work in Gemini 3.1. It has the prompt formula that makes answers sharper, plus the exact modifiers and trigger phrases that switch on Google Search grounding, Workspace files, Deep Research, and image generation. Every table is copy-paste ready. For finished prompts built on these patterns, see the best Gemini prompts and Gemini prompt templates.

The ICC formula

Almost every strong Gemini prompt has three parts in the same order: Intent, Context, Constraints. State what you want, give Gemini what it needs to know, then set the rules for the output.

Here is the same formula with each part labeled, so you can see how they slot together:

[Intent] Write a launch announcement email for our new analytics dashboard.
[Context] Audience is existing customers on the Pro plan. The dashboard adds real-time charts and CSV export. Tone should match our friendly, plain-spoken brand voice.
[Constraints] Under 150 words. One clear call to action ("View your dashboard"). No hype words, no exclamation marks. Return only the email body with a subject line above it.

You do not need the literal bracket labels once you are used to it — just keep the three ideas in that order. Grab a role from the next table, a format from the one after, and drop them into the Constraints line. For deeper walkthroughs, see the best Gemini prompts.

Role modifiers

Open a prompt with a role to set Gemini's perspective, vocabulary, and standards. Put it at the start of the Intent line.

Output-format modifiers

Gemini 3.1 follows explicit format instructions reliably. Add one of these to the Constraints line so the output arrives in the shape you need.

Thinking levels

Gemini 3.1 lets you set how hard it reasons before answering — Low, Medium, or High. Higher levels are slower and cost more, so match the level to the difficulty.

Rule of thumb: if a wrong answer is expensive or the problem has several moving parts, raise to High — ideally on Gemini 3.1 Pro. For volume and speed, keep 3.1 Flash on Low or Medium.

Feature triggers

These phrases switch on specific Gemini features. Include one when you want live data, your own files, a full report, a canvas, or an image.

Combine triggers with ICC — for example, an Intent of "give me a cited report" plus Context of "for a US B2B audience" plus Constraints of "under 1,000 words, table of vendors" gives Deep Research a tight brief. See how to prompt Gemini for Deep Research for the full workflow.

Gems — what to save

A Gem is a saved custom assistant that keeps its instructions across every chat. Build one for any task you repeat, and put your standing ICC setup inside it so you never retype it.

Good Gems to build: a brand-voice writer, a code reviewer, a study tutor for one subject, a meeting-notes summarizer wired to your Workspace. Use a one-off prompt for anything you only do once.

Example prompts

Six complete prompts assembled from the tables above — a role, a format, and where useful a feature trigger, all wrapped in ICC.

1. Grounded market summary

Act as a market analyst. Give me the current state of the consumer robot-vacuum market. Search the web and use up-to-date sources as of today. Return a table with columns: Brand, Flagship model, Price band, One standout feature. Then add three bullet points on where the market is heading. Cite your sources with links. Keep it under 300 words.

Best for: fast, sourced overviews. (Grounding on, Medium thinking)

2. Workspace report summary

Act as a data analyst. Summarize the attached Q2 Performance Report Doc for our leadership team. Context: they have five minutes and care about revenue, churn, and one risk. Constraints: a one-line summary at the top, then three headed sections (Revenue, Churn, Risk), each two sentences max. No jargon. Pull exact numbers from the document.

Why it works: names the file, sets the audience, and caps the length. (Workspace on)

3. Deep Research brief

Do deep research on the best project-management tools for a 20-person design agency in 2026. Context: we use macOS, live in Slack, and need Gantt views plus time tracking. Constraints: return a cited report under 1,000 words with a comparison table (Tool, Price per user, Gantt, Time tracking, Verdict), then a single recommendation with reasons. Flag anything you are unsure about.

Best for: vendor and tooling decisions. (Deep Research, High thinking)

4. Code review with High thinking

Act as a staff software engineer doing a careful code review. Context: this is a Python function that batches API calls; it will run in production against a rate-limited endpoint. Review it for correctness, edge cases, and rate-limit handling. Constraints: list issues as numbered items, each with severity (high/medium/low) and a one-line fix. Then show the corrected function, code only. [paste your code below]

Best for: catching real bugs. (Gemini 3.1 Pro, High thinking)

5. Study explainer as a table

Act as a patient tutor. Explain the difference between mitosis and meiosis to a first-year biology student. Context: I understand basic cell structure but mix these two up. Constraints: return a comparison table with columns: Feature, Mitosis, Meiosis. Then give one plain-English memory trick. Keep the whole answer under 200 words.

Why it works: role plus a strict format keeps it simple and scannable. (Low thinking)

6. Brand email in JSON

Act as our senior copywriter. Write a re-engagement email for lapsed free-trial users. Context: friendly, plain-spoken brand voice; the product is a budgeting app; offer is 30% off the first year. Constraints: return valid JSON only, matching {"subject": string, "preheader": string, "body": string}. Body under 120 words, one call to action, no exclamation marks, no hype words.

Best for: plugging output straight into an email tool. (Medium thinking)

Want ready-made skeletons instead of writing from scratch? Grab Gemini prompt templates, or browse the best Gemini prompts for finished examples.