Sometimes it's the simple things that make the best accessories. These initiative cards answer the age old question that's bedeviled gamers for as long as games have existed: Who's turn is it?
The cards are much more useful than just determining initiative. There are monster cards, character cards, and end of round cards for concluding effects. All of the cards are editable in Adobe.
The character cards cover class, race, level, AC, all the d20 attributes and saves, speed, vision, select skills useful in hiding and spotting, languages, and special notes. The monster cards are similar but more open-ended, with space for attacks, open-ended skills, and a scratch area for hit points.
The cards all have a spot in the top right for initiative. The game master records initiative on each card, shuffles the deck accordingly, and then cycles through the cards and each opponents' actions. Since there's limited space to fill in initiative, it's likely game masters will be printing multiple sheets of these for each character and each encounter.
This concept – cards as a critical accessory to role-playing games – is so intuitive that it eventually became a proper part of Dungeons & Dragons 4th Edition. These cards can also be used for a variety of D20 games that use similar statistics. And best of all, it's free!