[Magic] Concussion Spell OP?

[VariousRen]

Myself and several other players in a low tech fantasy game recently held a free for all tournament while our GM was away to fill our weekly time slot. During the fight between the 5 of us, one of the wizards began slinging 2FP (1 after skill reduction) concussion spells every other round, and we realised how powerful this spell is.

For two points (or 1, if the DM allows it to do no damage), everyone in a 10 yard area must make a HT-3 roll or be stunned. For an average 10 HT character (we are all low points, so HT is rarely higher than 10 or 11) this is a fail 87% of the time. Every round after also requires another HT-3 roll to recover from stunning, resulting in ~8 rounds on average of being stunned on the ground. Once you recover, the wizard charges another concussion spell, you have one round to do something (like recover the weapon you dropped, or stand up), and then they throw it at you again.

Is there anything I am missing with this spell, or does it need to be changed to bring it in line with other damage & disable spells such as lightning bolt?

[brianfb]

Its a loud spell, it will potentially attract unwanted attention.

It also affects,nearby allies.

[vorpalvitto]

The spell also affects the mage who cast it if he is within 10 yards of where the explosion originates from. Which means that he must be at least 11 yards away to be safe from his own spell.
Shooting at something 11 yards away yields a -5 penalty to his attack roll, so even with the +4 bonus of aiming at the floor he still has a -1 penalty to hit. How high is his Innate Attack skill? If his attack misses there is a chance that the attack lands closer to him (you randomly determine in which direction the attack missed and the distance by which it missed is the margin of failure) than anticipated.

But otherwise even in a low point game mages can be very powerful with battlefield control spells.

[Gnome]

Well yes, it's a bit OP. I've sometimes house ruled that recovery is straight HT.

Also, note that you don't get knocked over, nor do you drop your weapons (you're probably thinking of knockdown, which sometimes accompanies stunning but not always). And of course with any missile spell you have to cast it first, creating a visible ball of swirling winds (or whatever the GM describes) in your hand. Anyone seeing that should either take cover, charge the wizard, or clamp their hands over their ears. I would argue the latter counts as Protected Hearing, although of course it occupies two hands.

[Bruno]

The spell wasn't written for this kind of "gladiatorial" game. In more usual gameplay, I've found it's pretty amply controlled by that unmodifiable 10 yard radius, which has an incredible tendency to catch team-mates.

[Anaraxes]

There's also a bit of a lesson here to the effect that HT is more valuable than you might think -- and there's a reason adventurer types often take High Pain Threshold and Combat Reflexes.

An archer might also be useful.

Once you get within 10 yards, you're safe unless the mage wants to catch himself in the blast. And a staggered charge would mean that someone's going to get within 10 yards. Forming a nice little cluster of 4 people that are all trying to melee each other while ignoring the mage, on the other hand, will work as poorly as described in the OP. Which is a nice example of the way that tactics matter in GURPS, not just your HP and THAC0.

[Gnome]

Originally Posted by Anaraxes

Once you get within 10 yards, you're safe unless the mage wants to catch himself in the blast.

Not necessarily. For example, if you're five yards from the mage he can throw it 10 yards behind you, 15 yards from himself, catching you in the blast but comfortably staying outside of its range himself. (Assuming an infinite featureless plane, yadda yadda.)

[Anaraxes]

Originally Posted by Gnome

he can throw it 10 yards behind you

True enough. On the bright side, it's then well out of range of the other three people attacking from the other three cardinal points :)

[ericthered]

If the spell is OP, its because its priced as a damage spell with a side effect but you are using low cost versions of the spell purely for the side effect.

A completely non-RAW houserule would be to base the HT roll penalty on the dice of damage -- a 2d missile requires HT-2, a single energy point that does no damage (as has been suggested above) is against HT, and so on.

[Mailanka]

On the other hand, GURPS Magic is not well known for its excellent balance.