When does "on your turn" happen?

[Ilium]

One of the PCs in my group uses the CA spell Ring of Blades. The spell description says something to the effect of "each round on your turn the blades do damage to all creatures in adjacent squares." This is a paraphrase because I don't have the book handy, but the question is when does "on your turn" happen? Is it at the beginning of your turn? The end? Continuously so that you can damage a dozen foes by running between them (I assume not!).

Further details for those who care:

For the duel he was in I had the spell do damage at the beginning of the caster's turn, but this means the foe can just 5-foot step away all day and never take damage from the spell. On the other hand, if it's the end of the caster's turn, the spell will never damage melee monsters that the caster is retreating from.

 

[Infiniti2000]

The errata says:

Page 121: Ring of Blades
The second sentence of the spell’s description should be changed as follows: Each round at the end of your turn, starting the round in which you cast the spell, the blades deal 1d6 points of damage +1 point per caster level (maximum +10) to all creatures in the affected area.

The Spell Compendium has a change in it as well.

Fwiw, we've also houseruled the duration to 1R/L.

 

[kjenks]

Body of the Sun has the same wording.

 

[Ilium]

The errata says:
The Spell Compendium has a change in it as well.

Fwiw, we've also houseruled the duration to 1R/L.

Ah, thanks. I assume that would apply to all spells with similar wording. That makes it "offenseive mode." Opponents can't escape the damage if you move next to them, but you don't do any damage if you are moving away from them.

The duration does seem kind of long. I think the idea behind the spell is that it's defensive (so the duration is similar to Shield) but the PC in question actually won his duel by forcing his opponent against a barrier and cutting him up with the Ring of Blades.

 

[Infiniti2000]

That makes it "offenseive mode." Opponents can't escape the damage if you move next to them, but you don't do any damage if you are moving away from them.

Agreed. But double-check the Spell Compendium, if you have it. I think that has the opposite wording. We use the errata (as only one person in our group has the SC).

The duration does seem kind of long. I think the idea behind the spell is that it's defensive (so the duration is similar to Shield) but the PC in question actually won his duel by forcing his opponent against a barrier and cutting him up with the Ring of Blades.

Above you said it's offensive, and I agree. It's not a buff spell or a protective spell. You can't even get close to allies to heal them (without special abilities like Reach Spell). We play it as 1R/L and as the cleric of the party, I readily admit that's plenty long enough.

As full disclosure, however, I'll point out that I use it as a purified ring of blades and my party is all of Good alignment.

 

[KarinsDad]

We've house rule all duration area spells to occur at four points in time:

1) When anyone enters the area.
2) When the spell is cast on round one.
3) At the end of the caster's turn (assuming his init has not changed) in rounds other than round one.
4) At the caster's init when the spell was cast if his init has changed.

So, Ring of Blades, Wall of Fire, Evard's Black Tentacles, it does not matter. All of these types of spells work the same and have the same "when" mechanics in our game.

This does several things:

1) The caster of Ring of Blades cannot move around the battlefield and damage dozens of opponents along his move path. He can only offensively use the spell to damage any opponents next to him at the end of his turn (i.e. the most he could get is 8 opponents and even then, he would have to fly or dimension door into a square with 8 opponents surrounding it).

2) Ring of Blades is a defensive spell since any opponent who closes within range of them is damaged on their turn (when they first enter the area) as well as on the caster's end of turn (if he stays put).