Single Player Adventure.

[SoD]

If I were running an adventure with one person (let's say it's a first level adventure) that is, myself (DM) and one PC...what level should the PC be? What about if I made the PC a gestalt character?

[Gaiwecoor]

One good resource I've found is the Encounter Calculator, over at Pen, Paper & Pixel (http://www.penpaperpixel.org/tools/d20encountercalculator.htm)

According to that thing, one level four character should have a similar "party level" to a four character level one party. If it's gestalt, raise the effective party level by one. Thus, a three level gestalt character is the same party level as a four character non-gestalt party.

[Toliudar]

You may need to be ready to revamp certain sections of any pre-made adventure to accommodate a solo player. Here are a few of the strategies I've used:

Generally, not more than 3 opponents at a time, and avoid those with save-or-lose effects (hold, charms, etc) unless you're ready, plot-wise, to deal with the consequences.

Gestalt does help, but the player can still only do one thing in a round. Having an animal companion, or better yet an NPC companion, will take a lot of the pressure off. An NPC can also be a voice for whenever you need to hit the player with the clue bat, if they're stuck or going drastically off course (Sometimes drastically off course can be fun.).

Social interaction, intrigue and mystery can be great elements in a solo campaign. Film noir is a great source of inspiration for this.

Best of luck!

[SoD]

Thanks, I've just been thinking about trying to get my younger sister into DnD. We don't normally see eye-to-eye about, well, anything. But lately there's been literally no disagreement for months. Plus, if it fails, I'll give my cousin a go, the only reason I haven't tried him already is his age, but now he'd be fine with it.

[Gaiwecoor]

Gestalt does help, but the player can still only do one thing in a round. Having an animal companion, or better yet an NPC companion, will take a lot of the pressure off. An NPC can also be a voice for whenever you need to hit the player with the clue bat, if they're stuck or going drastically off course (Sometimes drastically off course can be fun.).

Absolutely seconded. I'd recommend keeping the NPC two levels lower than the PC, though. If the PC is higher level, it helps keep them in the spotlight. As such, I'd recommend starting at PC level 3, NPC (DMPC) level 1. As has been said, gestalt helps, but they each still get one action per round.