K, so you've played a couple of sessions of Swords & Wizardry Light and your players' characters are all maxed at Third Level, as that is as far as the 4-page folio will take you. What are your options?
Well, you could convert your campaign to Swords & Wizardry Complete. I'll be putting together some conversion guidelines in the next few weeks. Its mostly common sense and is certainly an easy way to continue your campaign.
In the next few months we'll be releasing the Swords & Wizardry Expert / Extra / Enhanced / Whatever We Call It Light Rules. About 16 pages of rules taking your campaign to level 7, with magic items, traps, new classes, new spells, new monsters and more. Tack on 7 one and two page adventures and maybe a small setting and we should come in around 28 to 32 pages. But that's later. Its not now.
Your other option is to keep playing at Third level, but allow the PCs to improve as they adventure further. How so?
Here's how Perks work. After attaining 3rd level, PCs can still accumulate game session "credit" and they can spend this "credit" as follows:
1 Credit - Add 1 HP to the HP total. Can buy this Perk a maximum of 10 times. Note, these are not HD and a Constitution Bonus does not apply.
2 Credits - Lower Saving Throw by 1 point. Can buy this perk a maximum of 5 times.
2 Credits - Fighter Only - + 1 to BAB - Can buy this Perk a maximum of 3 times.
2 Credits - Cleric and Magic-User Only - Add 1 First Level spell slot - Can buy this Perk a maximum of 3 times.
3 Credits - Cleric and Thief Only - + 1 BAB. Can only buy this perk once.
4 Credits - Thief Only - Add a 1 in 6 chance to Thief Skills. This Perk may only be bought once.
4 Credits - Magic-user Only - Add 1 Second Level spell slot. Can only buy this Perk once.There you have it. A way to make three levels a tad more than three levels. Kinda like Spinal Tap without all the deaths of drowning in vomit ;)