After GMing PFS at conventions for 2 years and 60 tables I have built up a long mental list of things I do to fully prep a scenario for convention play. This list has remained relatively stable throughout this year so I decided to share it for 2 purposes:

1. to see if I could optimise and streamline it for faster and easier prep
2. to create a formal check list

I hope that it is useful to others and that there are suggestions for improvements.

Getting started

1. Print out scenario text pages, and put in a lightweight binder.
2. Use a highlighter to highlight all notable scenario text, plus reference information such as treasure, terrain, ceiling height, light level.
3. Mark all skill checks in scenario text so they are easily spotted (I just circle DCs)
4. Mark where all faction missions are in the scenario so you don’t accidentally skip over them when running the scenario (I use a different colored highlighter on faction names)
5. Using Combat Manager/PRD/PFSRD - Save and print out all stat blocks that are not fully listed in scenario

Encounters

1. Lookup all monster special abilities and traits. Make notes and print out any large text blocks you need.
2. Highlight all key features of creatures and make notes for things you may miss. For example note power attack bonuses next to attacks, and flag other combat maneuvers such as step up or lunge. Note defensive abilities and items prominently next to defensive stats, such as DR, SR, Shield, ring of Counterspells.
3. Review tactics and work out what you will do and what you need to know for round one.
4. Note any items they have that affects combat.
5. Using PRD/PFSRD/combat manager: lookup all feats you aren’t sure of.
6. Using PRD/PFSRD/combat manager: lookup all abilities/spells you aren’t sure of and make notes. Noting in short:  range, radius, effect, non-std casting time
7. Note any build errors you find and work out what you will do about them. For example an NPC has a feat he doesn’t qualify for or the tactics mention a spell that can’t be used. (Assume if you don’t find any build errors that you missed them. It is nigh impossible to create multiple NPC characters without making mistakes, especially higher level ones.)
8. Note any environment conditions that affect the encounter: obstacles, terrain, lighting, ceiling height, etc.
9. Once you have reviewed the above and know the constraints you are working under then work out what leeway you have to make the encounter more intelligent, fun, harder, softer.
10. If any elements are new to you or it looks too weak or too deadly then do a dummy run of round one of combat to look for issues or options.
11. Think about any PC abilities or PC types that might sideline an encounter, eg. Sleep Hex.
12. Print out any unusual monster pictures.

Story and RP

1. Read entire scenario to identify story elements, any potential holes, any stall points or any story thread weaving required. Note any elements that need to be brought out or hinted at.  
2. Identify every NPC and give them a basic personality, typically by aligning them to someone from real life or fiction (your own family and friends, work colleagues, the Simpsons, etc). Though it may be bad form to base it on someone actually sitting at the table ;-)
3. Read every faction mission and work out where and how to surface it, any potential issues..
4. Try and spot any assumptions that might break the story if they don’t come true and how to work around them. For example does any outcome depend on encounters being resolved the traditional way rather than via enchantment spells or social skills.
5. Lookup any scenario relevant rules that might come up, for example: cold weather, drowning.

Admin

1. Print 2-3 copies of faction missions and any handouts, cut out and file
2. Print out 6 chronicle sheets per session planned plus one for GM credit.
3. Print out reporting/tracking sheet if required.
4. Print and fill out initiative cards for all creatures (location, subtier, number, name, initiative, AC, HP)
5. Print blank initiative cards for PCs (fields: name, level, classes, Initiative, Perception, Sense Motive, Will Save, specials, PFS number, faction)
6. Create event/scenario on Paizo or get event number from coordinator
7. Create and print out sign-up sheet where required for that particular convention
8. Pre-fill chronicle sheets with event name, event ID and GM ID to save table time
9. Print out images from the scenario for scene setting (using print screen and Paint.Net).
10. Complete any enemy spellbook spell lists and print off as handouts
11. If it is to be run in a short slot, prepare a handout of mission goals and key NPC names.
12. Identify any flip mats or alternative maps you can use (and any you want to buy)
13. Print or pre-draw any complex maps or key parts of maps
14. Identify and find any minis required. Find proxies or print tokens for any you don’t have.
15. Charge any electronic devices you intend to use.

Beyond the scenario / Extra Mile (optional)

1. Read the wiki for all locations and people listed in the module
2. Print any scene setting images from the wiki
3. Identify any scenery or props you could use or make to add some depth and fun. Particularly where it is necessary to identify who is carrying a particular item. For example an important key, scroll, wayfinder or other scenario maguffin.
4. Contribute to the GM thread any errors, concerns, questions, or notable table points.
5. Write a review of the scenario. Doing this before you run it forces you to think through the scenarios strengths and weaknesses. Update after you run it. This is the main way you can influence authors to write the kind of scenarios you want to run or play. Be constructive and use spoiler tags.
6. Create handouts for knowledge checks