minimum stats needed for fighter => cleric?

Joey

what are the minimum stats needed to dual a fighter to a cleric? Also what's the best level to do it at?

Any other general advise? Thinking of dual-weilding hammers, lawful good.

Eudaemonium

15 Strength, 17 Wisdom.

For level, 7, 9 or 13 are the popular options, but I haven't ever done it personally so I can't really advise.

Lord_Tansheron

For BG2, dual at 9 unless you are a very experienced player or running a very small party/solo run. 13 is a big step up for what is essentially +0.5APR, and only recommended if you can metagame experience gains to the max.

TJ_Hooker

Some things to keep in mind: fighters gain a proficiency point every 3 levels, and an extra half an attack per round at levels 7 and 13.

So here are some common levels to dual at:
3: +1 proficiency, regain your abilities after dualling quickly
6: +1 proficiency, highest you level you can dual and still regain abilities in BG1
7: +0.5 APR, regain abilities quickly in BG2
9: +1 proficiency, maximixed HP (fighters gain d10 + full CON bonus for levels 1 through 9, afterward they only get +3 HP per level), regain abilities somewhat quickly in BG2
12: +1 proficiency, but if you've gone this far, you might as well go till level 13
13: +0.5 APR. As @Lord_Tansheron mentioned above, you're paying a fairly steep price for this half an attack, so you should only go this far if you're determined to wring every last drop out of your fighter levels.

Lord_Tansheron

Also of note is that you gain extra uses of your kit's special ability (Kai, Berserker Rage) at levels 5, 9, and 13 (every 4 levels).

Corvino

If you're planning to dual, it's almost always better to dual fighters at 7 (+1/2 APR), 9 (max fighter HP, grandmastery) or 13 (+1/2 APR). None of these options will allow you to regain your fighter levels during BG1 or BG:EE, and are only really feasible in BG2. Dualling at 9 is probably the best compromise in terms of speed of regaining levels against benefit from additional fighter levels, as @TJ_Hooker says.

Berserker is the normal fighter kit of choice for dualling to Cleric, as the rage gives a number of choice immunities and the downside is practically non-existent.