+2 or +1 and Keen Rapier at 8th lvl?

[Jens]

It sure does depend on Str and how often you hit. Assuming you have WS, a Str bonus of around +12 and hit about three times out of four, the two are about equal (If you're weaker or hit less often, the extra 'plus' is better.)

So most likely, you'll be better off with upgrading to +2 (I actually thought Keen was better than that?!). As others have said, an energy effect would be even better, though.

Ratio of new damage to old: (assuming SW but no Str bonus, and that you hit on 11+)
Keen: 1.30/1.15 = 1.13 (if susceptible to crits)
+2: (3.5+4)/(3.5+3) * 11/10 = 1.27 (and ignores DR +2)
Flaming: [(3.5+3)*1.15+3.5]/[(3.5+3)*1.15] = 1.47 (if not flame resistant)

 

[CRGreathouse]

Keen generally deals the least damage [on low- to mid-levels], increases randomness (bad), and is conditional.

Flaming/Shock/Frost deals the most damage on average, does not affect randomness, and is conditional.

+2 deals damage between the other two, decreases randomness (good), helps against DR, and is unconditional.

 

[Lord Ben]

As a DM if my players have +2 weapons I might not look for a Dr X/+2 creature to put against them. But if they all have +1 flaming weapons I'll be looking for that CR7 Earth elem with DR /+2 to show them their errors!

My favorite is a spell storing weapon.

 

[Darkness]

As a DM if my players have +2 weapons I might not look for a Dr X/+2 creature to put against them. But if they all have +1 flaming weapons I'll be looking for that CR7 Earth elem with DR /+2 to show them their errors!

My favorite is a spell storing weapon.

So you'd punish your players for not getting +2 weapons, but if they did get them, they wouldn't even have needed them?

 

[Lord Ben]

So you'd punish your players for not getting +2 weapons, but if they did get them, they wouldn't even have needed them?

That's one way of wording it! I prefer to say that I put interesting encounters into a module! If they go off and spend their loot on +1 flaming weapons I'm not going to say "The next module is Earth Elemental cave!! hahahaah" But there might just be one of the encounters like that in there. It presents and interesting challenge. Just like if a PC took hold the line I'd make sure to charge on occasion, or if they took combat reflexes I might have a horde of orcs run past and let them chop the first 5 down.

 

[Hammerhead]

Get a +1 Energized weapon, then get the party cleric to GMW your rapier, making it at least +2. If he has a Bead of Karma, it goes to +3.

For style, however, go with Keen.

 

[Disease]

I would go +2.

You'll never have to worry about your weapon being effective that way.

 

[dead_radish]

There is the fact that if you take Keen, then at level 9 you can take improved critical (rapier). And get a 12-20 threat range. If you're hitting things fairly often, you've got a 45% chance per attack of threatening. Now if you reallllly need that +1 to attack, then take the +2. Otherwise, I'd say take Keen, and do +3.5 damage 45% of the time (actually a bit less, but still).

And then next time, get flaming burst.

 

[Jondor_Battlehammer]

I think I'm going with the majority on this one. At your level, keen is a safer bet. Course, Keen + Improved Crit with a Rouge is very dangerous. Either would serve you well.

 

[Celebrim]

I'm going to vote with the majority on this one as well. Take the +2 bonus over keen. I'm going to go a little further out on the limb and say take the +2 bonus over flaming (for sure), shock, or frost.

As has already been adequately shown, keen adds (usually) less than +1 avg. damage to your attacks. It is also useless against a wide range of opponents. The only reason to take Keen (IMO) is if you already have a high enough bonus that you overcome most (non-epic) damage resistances, OR (maybe) if you stand a reasonable chance of doing more than 50 points of damage with every critical. For example, I'd probably take a +3 keen rapier over a +4 rapier. I'd also consider a +2 keen greataxe over a +3 greataxe if my damage bonus was already +11 or better - if only for the coolness factor of provoking the occasional massive damage save.

There are several likely choices for DR ##/+2 at your CR: Kytons and any infernal creature with 12+ HD come to mind. Sooner or latter the DM is going to want to throw a Clay Golem your way. If he is anything like me, he is going to throw a mix of creatures at you. Against some of them keen might provide a slight advantage, but there are far more where +2 provides an absolute advantage.

There are a variaty of problems with energy weapons. Flaming is the worst of them (for a rouge), both because alot of things that you run into are going to have fire resistance or be of the fire subtype and flaming is going to do nothing for you, and because the DM is going to almost certainly rule carrying around a 'torch' is hazardous to your stealth. Also, activating the flaming ability on a weapon is a standard action, so if you are in a campaign were blades stay sheathed (to avoid unsettling the natives) or need to be sheathed (so you can disable a trap etc.) flaming is probably a bad choice. The fact that you won't be able to attack in the first round will greatly outweigh the increased damage you do in latter rounds in a large number of situations. If you must take an energy weapon, I'd take shocking, but NOT before I got a +3 weapon. A +3 keen shocking rapier would be an excellent weapon.

On the other hand, if you aren't sneaky to begin with, flaming is nice because _you are carrying a torch_, and fire has nearly infinite uses.

Energy weapons are good choices for missile weapons such as bows since the effect only comes into effect when the missile is fired (in any ruling I'm familiar with), and thus the limitation on activation is not really a problem (since you can easily keep them always active).

Please no one claim that you can keep an active flaming weapon in a scabbard. We've been there already.