# Contesting Casts of Control Weather

If two opposing casters are both attempting to cast Control Weather and maintain control, both desiring different effects, how is that conflict resolved?

• Are these two PCs or a PC and NPC/monster? Aug 2, 2017 at 18:28
• These would be two NPC casters, one allied with the players and the other against them. Aug 2, 2017 at 18:29
• Related (or, at least, similar): Can two characters use call lightning from the same storm?
– nitsua60
Aug 2, 2017 at 18:50

Control Weather defines precipitation, temperature and wind in 5-6 stages each.

It allows you to find a current condition and change its stage by one. This takes 1d4×10 minutes, after that you can change it again.

You can change precipitation, temperature, and wind. It takes 1d4 × 10 minutes for the new conditions to take effect. Once they do so, you can change the conditions again.

[…]

When you change the weather conditions, find a current condition on the following tables and change its stage by one, up or down.

When two casters change the weather they each can change one condition by one stage every 1d4×10 minutes.

## Example:

Mage A wants to increase precipitation and rolls a 2. Over the next 20 minutes, the precipitation increases by 1 stage.

Mage B wants to decrease precipitation and rolls a 1. Over the next 10 minutes, the precipitation decreases by 1 stage.

Mage B can now change the weather again. He chooses to repeat his step and rolls a 1 again.

After a total of 20 minutes precipitation was decreased by 2 stages and increased by 1, thus overall decreased by 1.

### The "Most Potent" casting takes effect for the duration:

As defined on the PHB pg. 205:

The effects of the same spell cast multiple times don't combine, however. Instead, the most potent effect-such as the highest bonus-from those castings applies while their durations overlap.

In this case, the same spell (Control Weather) is being cast multiple times, which means that the most potent cast takes effect as long as both spells are active.

### How do we determine potency?

Unfortunately, potency doesn't really have a hard definition. In this case, there are no bonuses to apply, no saving throws to look to, a similar duration, and an equally potent effect (increasing or decreasing the "stage" of weather by 1). Which means that the DM has to make a call based on some other criteria.

For example, the higher level caster may be considered "more potent" and casts "more potent" spells and so overrides a lower level caster. Or, if one creature casts the spell at a higher spell level, that spell could also be considered "more potent". Regardless of whatever the DM chooses, once one caster has the "more potent" spell, the effect of that caster's spell takes effect for the duration, effectively hiding the other caster's spell from functioning until the "more potent" spell ends.

### That isn't very cinematic...

There isn't a whole lot of drama using this method. One caster's spell beats the other, and then only one spell effect takes place until the most potent spell ends. The casters never really wrestle with the effects of each other's spells. For a more cinematic approach that adds more drama, Thyzer's answer is much better suited. But that approach is arguably not strictly RAW, though I believe more enjoyable overall.

• +1, but I think that "the effects of the same spell cast multiple times don't combine" does not necessarily mean that the spells by itself do not combine, just the effects of them don't. Like changing the wind direction from north to south and another caster changes it from west to east does not mean that it comes from northwest to southeast. This is just an assumption, feel free to prove me wrong, I am not sure myself. Aug 2, 2017 at 19:01